TWI744207B - Anode active material, mixed anode active material material, and method for manufacturing anode active material - Google Patents

Anode active material, mixed anode active material material, and method for manufacturing anode active material Download PDF

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TWI744207B
TWI744207B TW110111252A TW110111252A TWI744207B TW I744207 B TWI744207 B TW I744207B TW 110111252 A TW110111252 A TW 110111252A TW 110111252 A TW110111252 A TW 110111252A TW I744207 B TWI744207 B TW I744207B
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negative electrode
active material
electrode active
salt
particles
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TW202139505A (en
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廣瀨貴一
高橋廣太
松野拓史
酒井玲子
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日商信越化學工業股份有限公司
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Abstract

本發明是一種負極活性物質，其包含負極活性物質粒子，該負極活性物質的特徵在於：負極活性物質粒子含有矽化合物粒子，該矽化合物粒子包含矽化合物SiO x，其中，0.5≦x≦1.6；矽化合物粒子含有鋰化合物；負極活性物質粒子包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽，且包含金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。藉此，本發明提供一種負極活性物質，其在製作二次電池的負極時能夠使所製作的漿料穩定化，且在作為二次電池的負極活性物質使用時，能夠提升起始充放電特性和循環特性。 The present invention is a negative active material comprising negative active material particles. The negative active material is characterized in that the negative active material particles contain silicon compound particles, and the silicon compound particles contain silicon compound SiO x , wherein 0.5≦x≦1.6; The silicon compound particles contain a lithium compound; the negative electrode active material particles contain at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose, and contain a metal salt, and the metal salt contains at least one selected from magnesium and aluminum Metal. Thereby, the present invention provides a negative electrode active material, which can stabilize the prepared slurry when producing a negative electrode of a secondary battery, and can improve initial charge and discharge characteristics when used as a negative electrode active material of a secondary battery And cycle characteristics.

Description

負極活性物質、混合負極活性物質材料、及負極活性物質的製造方法Anode active material, mixed anode active material material, and method for manufacturing anode active material

本發明有關一種負極活性物質、混合負極活性物質材料、及負極活性物質的製造方法。The present invention relates to a negative electrode active material, a mixed negative electrode active material material, and a manufacturing method of the negative electrode active material.

近年來，以行動式終端等爲代表的小型電子機器廣泛普及，而強力要求進一步小型化、輕量化及長壽化。針對這種市場要求，推進了一種二次電池的開發，該二次電池特別小型且輕量，並且能夠獲得高能量密度。此二次電池的應用不限定於小型電子機器，對於以汽車等爲代表的大型電子機器、以房屋等爲代表的蓄電系統的應用也正在研究之中。In recent years, small electronic devices represented by mobile terminals have become widespread, and there is a strong demand for further miniaturization, weight reduction, and longevity. In response to such market requirements, the development of a secondary battery has been advanced, which is particularly small and lightweight, and can achieve high energy density. The application of this secondary battery is not limited to small electronic devices, and the application of large-scale electronic devices represented by automobiles, etc., and power storage systems represented by houses, etc. are also being studied.

其中，鋰離子二次電池易於實行小型化及高容量化，並且，能夠獲得比鉛電池、鎳鎘電池更高的能量密度，因此備受期待。Among them, lithium-ion secondary batteries can easily be miniaturized and increased in capacity, and can obtain higher energy density than lead batteries and nickel-cadmium batteries, and are therefore highly anticipated.

上述鋰離子二次電池具備正極和負極、隔板、及電解液，且負極包含與充放電反應相關的負極活性物質。The above-mentioned lithium ion secondary battery includes a positive electrode and a negative electrode, a separator, and an electrolyte, and the negative electrode contains a negative electrode active material related to a charge and discharge reaction.

作爲此負極活性物質，廣泛使用碳系活性物質，另一方面，最近的市場要求進一步提升電池容量。爲了提升電池容量，正在研究使用矽來作爲負極活性物質材料。原因在於，矽的理論容量(4199 mAh/g)比石墨的理論容量(372 mAh/g)大10倍以上，因此可期待大幅提升電池容量。作為負極活性物質材料的矽材料的開發，不僅對於矽單體，對於以合金、氧化物爲代表的化合物等也正在研究中。又，活性物質形狀，正在研究從由碳系活性物質所實施的標準塗佈型到直接沉積在集電體上的一體型。As this negative electrode active material, carbon-based active materials are widely used. On the other hand, recent market demands further increase the battery capacity. In order to increase the battery capacity, the use of silicon as a negative electrode active material is being studied. The reason is that the theoretical capacity of silicon (4199 mAh/g) is more than 10 times larger than the theoretical capacity of graphite (372 mAh/g), so a significant increase in battery capacity can be expected. The development of silicon materials as materials for negative electrode active materials is being studied not only for silicon alone, but also for compounds such as alloys and oxides. In addition, the shape of the active material is being studied from a standard coating type implemented by a carbon-based active material to an integrated type directly deposited on the current collector.

然而，如果使用矽作爲負極活性物質的主原料，則在充放電時負極活性物質會膨脹、收縮，因此主要在負極活性物質表層附近容易碎裂。又，在活性物質內部會生成離子性物質，而使負極活性物質成為易於碎裂的物質。如果負極活性物質表層碎裂，則會因此導致産生新生表面，而活性物質的反應面積增加。此時，在新生表面會發生電解液的分解反應，並且在新生表面上會形成電解液的分解物也就是被膜，因此耗費電解液。因此，使循環特性易於降低。However, if silicon is used as the main raw material of the negative electrode active material, the negative electrode active material expands and contracts during charging and discharging, and therefore it is easily broken mainly near the surface of the negative electrode active material. In addition, ionic materials are generated inside the active material, and the negative electrode active material is easily broken. If the surface layer of the negative electrode active material is broken, a new surface will be generated as a result, and the reaction area of the active material will increase. At this time, the decomposition reaction of the electrolyte will occur on the fresh surface, and the decomposition product of the electrolyte, which is a film, will be formed on the fresh surface, so the electrolyte is consumed. Therefore, the cycle characteristics are easily degraded.

至此，為了提升電池起始效率和循環特性等，對於以矽材料爲主要材料的鋰離子二次電池用負極材料、電極構成進行了各種研究。So far, in order to improve the initial efficiency and cycle characteristics of the battery, various studies have been conducted on the negative electrode material and electrode structure for lithium ion secondary batteries using silicon materials as the main material.

具體而言，為了獲得良好的循環特性和高安全性，使用氣相法來使矽和非晶二氧化矽同時沉積(參照例如專利文獻1)。又，為了獲得高電池容量和安全性，在矽氧化物粒子的表層設置碳材料(導電材料)(參照例如專利文獻2)。進一步，為了改善循環特性並且獲得高輸入輸出特性，製作含有矽和氧之活性物質，並且在集電體附近形成氧比率較高的活性物質層(參照例如專利文獻3)。又，為了使循環特性提升，使矽活性物質中含有氧，且以下述方式形成：平均含氧量爲40 at%以下，並且在集電體附近的含氧量較多(參照例如專利文獻4)。Specifically, in order to obtain good cycle characteristics and high safety, a vapor phase method is used to simultaneously deposit silicon and amorphous silicon dioxide (see, for example, Patent Document 1). In addition, in order to obtain high battery capacity and safety, a carbon material (conductive material) is provided on the surface layer of silicon oxide particles (see, for example, Patent Document 2). Furthermore, in order to improve cycle characteristics and obtain high input-output characteristics, an active material containing silicon and oxygen is produced, and an active material layer with a high oxygen ratio is formed near the current collector (see, for example, Patent Document 3). In addition, in order to improve the cycle characteristics, the silicon active material contains oxygen and is formed as follows: the average oxygen content is 40 at% or less, and the oxygen content near the current collector is large (see, for example, Patent Document 4 ).

又，為了改善初次充放電效率，使用含有矽(Si)相、SiO 2、M yO金屬氧化物之奈米複合物(參照例如專利文獻5)。又，為了改善循環特性，將SiO x(0.8≦x≦1.5，粒徑範圍＝1μm〜50μm)與碳材料混合，並高溫煅燒(參照例如專利文獻6)。又，為了改善循環特性，將負極活性物質中的氧相對於矽的莫耳比設爲0.1〜1.2，並將活性物質控制在活性物質於集電體界面附近的莫耳比的最大值與最小值之差值成為0.4以下的範圍內(參照例如專利文獻7)。又，為了使電池負荷特性提升，使用含有鋰之金屬氧化物(參照例如專利文獻8)。又，為了使循環特性改善，在矽材料表層上形成矽烷化合物等疏水層(參照例如專利文獻9)。又，為了改善循環特性，使用氧化矽，並在其表層形成石墨被膜，藉此賦予導電性(參照例如專利文獻10)。在專利文獻10中，關於由與石墨被膜相關的拉曼光譜(RAMAN spectrum)所獲得的位移值，在1330 cm -1和1580 cm -1處出現寬峰，並且該等的強度比I 1330/I 1580爲1.5＜I 1330/I 1580＜3。又，為了高電池容量、改善循環特性，使用一種粒子，該粒子具有分散在二氧化矽中的矽微晶相(參照例如專利文獻11)。又，為了使過充電、過放電特性提升，使用將矽與氧的原子數比控制爲1：y(0＜y＜2)之矽氧化物(參照例如專利文獻12)。 [先前技術文獻] (專利文獻) In addition, in order to improve the initial charge and discharge efficiency, a nanocomposite containing a silicon (Si) phase, SiO 2 , and My O metal oxide is used (see, for example, Patent Document 5). In addition, in order to improve the cycle characteristics, SiO x (0.8≦x≦1.5, particle size range = 1 μm to 50 μm) is mixed with a carbon material and calcined at a high temperature (see, for example, Patent Document 6). In addition, in order to improve the cycle characteristics, the molar ratio of oxygen in the negative electrode active material to silicon is set to 0.1 to 1.2, and the active material is controlled to the maximum and minimum molar ratio of the active material near the interface of the current collector. The difference between the values is within the range of 0.4 or less (see, for example, Patent Document 7). In addition, in order to improve battery load characteristics, metal oxides containing lithium are used (see, for example, Patent Document 8). In addition, in order to improve the cycle characteristics, a hydrophobic layer such as a silane compound is formed on the surface layer of the silicon material (see, for example, Patent Document 9). In addition, in order to improve the cycle characteristics, silicon oxide is used, and a graphite film is formed on the surface layer thereof, thereby imparting conductivity (see, for example, Patent Document 10). In Patent Document 10, regarding the shift value obtained from the RAMAN spectrum related to the graphite coating, broad peaks appear at 1330 cm -1 and 1580 cm -1 , and the intensity ratio of these is 1330 / I 1580 is 1.5<I 1330 /I 1580 <3. In addition, in order to increase the battery capacity and improve the cycle characteristics, a particle having a silicon microcrystalline phase dispersed in silicon dioxide is used (see, for example, Patent Document 11). In addition, in order to improve the overcharge and overdischarge characteristics, silicon oxide in which the atomic ratio of silicon to oxygen is controlled to 1:y (0<y<2) is used (see, for example, Patent Document 12). [Prior Art Document] (Patent Document)

專利文獻1：日本特開2001-185127號公報 專利文獻2：日本特開2002-042806號公報 專利文獻3：日本特開2006-164954號公報 專利文獻4：日本特開2006-114454號公報 專利文獻5：日本特開2009-070825號公報 專利文獻6：日本特開2008-282819號公報 專利文獻7：日本特開2008-251369號公報 專利文獻8：日本特開2008-177346號公報 專利文獻9：日本特開2007-234255號公報 專利文獻10：日本特開2009-212074號公報 專利文獻11：日本特開2009-205950號公報 專利文獻12：日本專利第2997741號說明書 Patent Document 1: Japanese Patent Application Publication No. 2001-185127 Patent Document 2: Japanese Patent Application Publication No. 2002-042806 Patent Document 3: Japanese Patent Laid-Open No. 2006-164954 Patent Document 4: Japanese Patent Application Publication No. 2006-114454 Patent Document 5: Japanese Patent Laid-Open No. 2009-070825 Patent Document 6: Japanese Patent Laid-Open No. 2008-282819 Patent Document 7: Japanese Patent Application Laid-Open No. 2008-251369 Patent Document 8: Japanese Patent Application Laid-Open No. 2008-177346 Patent Document 9: Japanese Patent Application Publication No. 2007-234255 Patent Document 10: Japanese Patent Application Laid-Open No. 2009-212074 Patent Document 11: Japanese Patent Application Publication No. 2009-205950 Patent Document 12: Japanese Patent No. 2997741 Specification

[發明所欲解決的問題] 如上所述，近年來，以行動式終端等爲代表的小型電子機器的高性能化、多功能化不斷進展，其主要電源也就是鋰離子二次電池要求增加電池容量。作爲解决此問題的方法之一，期望開發一種鋰離子二次電池，其由使用矽材料作爲主要材料的負極所構成。又，當使用矽材料時，藉由使用摻雜有鋰之矽材料，能夠獲得高起始效率和容量維持率，但另一方面，使用摻雜有鋰之矽材料對於水系溶劑的穩定性低，而在製作負極時所製作的混合有矽材料之水系負極漿料的穩定性下降，因此在工業上並不適用。 [The problem to be solved by the invention] As described above, in recent years, small electronic devices represented by mobile terminals have been increasing in performance and multi-functionality, and the main power source, namely, lithium ion secondary batteries, is required to increase the battery capacity. As one of the methods to solve this problem, it is desired to develop a lithium ion secondary battery composed of a negative electrode using a silicon material as a main material. Also, when using silicon materials, high initial efficiency and capacity retention can be obtained by using silicon materials doped with lithium, but on the other hand, using silicon materials doped with lithium has low stability to aqueous solvents , And the stability of the aqueous negative electrode slurry mixed with silicon material made during the production of the negative electrode is reduced, so it is not suitable for industrial use.

本發明是有鑑於如前所述的問題而完成，其目的在於提供一種負極活性物質、及包含此負極活性物質之混合負極活性物質材料，該負極活性物質在製作二次電池的負極時能夠使所製作的漿料穩定化，且在作為二次電池的負極活性物質使用時，能夠提升起始充放電特性和循環特性。又，本發明的目的亦在於提供一種負極活性物質的製造方法，該負極活性物質在製作負極時能夠使所製作的漿料穩定化，且能夠提升起始充放電特性和循環特性。 [解決問題的技術手段] The present invention was completed in view of the aforementioned problems, and its object is to provide a negative electrode active material and a mixed negative electrode active material material containing the negative electrode active material, the negative electrode active material can be used in the production of the negative electrode of the secondary battery The prepared slurry is stabilized and can improve initial charge-discharge characteristics and cycle characteristics when used as a negative electrode active material of a secondary battery. In addition, the object of the present invention is also to provide a method for producing a negative electrode active material, which can stabilize the prepared slurry when producing a negative electrode, and can improve initial charge-discharge characteristics and cycle characteristics. [Technical means to solve the problem]

爲了達成上述目的，本發明提供一種負極活性物質，其包含負極活性物質粒子，該負極活性物質的特徵在於：前述負極活性物質粒子含有矽化合物粒子，該矽化合物粒子包含矽化合物SiO x，其中，0.5≦x≦1.6；前述矽化合物粒子含有鋰化合物；前述負極活性物質粒子包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽，且包含金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。 In order to achieve the above object, the present invention provides a negative electrode active material comprising negative electrode active material particles. The negative electrode active material is characterized in that the negative electrode active material particles contain silicon compound particles, and the silicon compound particles contain silicon compound SiO x , wherein: 0.5≦x≦1.6; the aforementioned silicon compound particles contain a lithium compound; the aforementioned negative electrode active material particles contain at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose, and contain a metal salt, the metal salt containing At least one metal selected from magnesium and aluminum.

本發明的負極活性物質，包含負極活性物質粒子(亦稱為矽系活性物質粒子)，該負極活性物質粒子包含矽化合物粒子，因此能夠提升電池容量。又，藉由矽化合物粒子包含鋰化合物，能夠減少在充電時產生的不可逆容量。藉此，能夠提升電池的初次效率和循環特性。又，藉由負極活性物質粒子包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽、及金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬，在製作使負極活性物質等分散於水系溶劑中而成之漿料(水系負極漿料)時，能夠抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，而提升水系負極漿料的穩定性。The negative electrode active material of the present invention includes negative electrode active material particles (also referred to as silicon-based active material particles). The negative electrode active material particles include silicon compound particles, and therefore can increase battery capacity. In addition, since the silicon compound particles contain a lithium compound, it is possible to reduce the irreversible capacity generated during charging. In this way, the initial efficiency and cycle characteristics of the battery can be improved. In addition, since the negative electrode active material particles contain at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose, and the metal salt, the metal salt contains at least one metal selected from the group consisting of magnesium and aluminum. When the negative electrode active material and the like are dispersed in the aqueous solvent slurry (aqueous negative electrode slurry), the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles can be suppressed, and the stability of the aqueous negative electrode slurry can be improved.

此時，較佳是：相對於前述負極活性物質粒子的總量，由前述聚丙烯酸的鹽和前述羧甲基纖維素的鹽中選出的至少一種鹽的總量，在0.1質量%以上且5質量%以下的範圍內。At this time, it is preferable that the total amount of at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose relative to the total amount of the negative electrode active material particles is 0.1% by mass or more and 5 Within the range of mass% or less.

若相對於負極活性物質粒子的總量，由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽的總量為0.1質量%以上，則能夠更抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，而更提升水系負極漿料的穩定性。又，若相對於負極活性物質粒子的總量，這種鹽的總量為5質量%以下，則能夠防止電池容量下降。If the total amount of at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose is 0.1% by mass or more with respect to the total amount of the negative electrode active material particles, it is possible to more suppress the content of the negative electrode active material particles. The lithium compound dissolves and precipitates lithium ions, which further improves the stability of the aqueous negative electrode slurry. In addition, if the total amount of such salts is 5% by mass or less with respect to the total amount of the negative electrode active material particles, the battery capacity can be prevented from decreasing.

又，此時，較佳是：由前述聚丙烯酸的鹽和前述羧甲基纖維素的鹽中選出的至少一種鹽是銨鹽。In addition, in this case, it is preferable that at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose is an ammonium salt.

若是這種鹽，則能夠更抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，因此更提升水系負極漿料的穩定性。If it is such a salt, the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles can be further suppressed, and therefore the stability of the aqueous negative electrode slurry can be further improved.

又，較佳是：相對於前述負極活性物質粒子的總量，前述包含由鎂和鋁中選出的至少一種金屬之金屬鹽的總量，在0.1質量%以上且5質量%以下的範圍內。Furthermore, it is preferable that the total amount of the metal salt containing at least one metal selected from magnesium and aluminum with respect to the total amount of the negative electrode active material particles is in the range of 0.1% by mass to 5% by mass.

若相對於負極活性物質粒子的總量，上述金屬鹽的總量為0.1質量%以上，則能夠更抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，而更提升水系負極漿料的穩定性。又，若相對於負極活性物質粒子的總量，金屬鹽的總量為5質量%以下，則能夠防止電池容量下降。If the total amount of the metal salt is 0.1% by mass or more relative to the total amount of the negative electrode active material particles, the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles can be more suppressed, and the stability of the aqueous negative electrode slurry can be improved. sex. In addition, if the total amount of the metal salt is 5% by mass or less with respect to the total amount of the negative electrode active material particles, the battery capacity can be prevented from decreasing.

又，較佳是：前述包含由鎂和鋁中選出的至少一種金屬之金屬鹽是硝酸鹽、磷酸鹽、鹽酸鹽及硫酸鹽中的任一種。Furthermore, it is preferable that the aforementioned metal salt containing at least one metal selected from magnesium and aluminum is any one of nitrate, phosphate, hydrochloride, and sulfate.

若是這種金屬鹽，則能夠更抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，因此更提升水系負極漿料的穩定性。If it is such a metal salt, it is possible to further suppress the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles, thereby further improving the stability of the aqueous negative electrode slurry.

又，較佳是：前述負極活性物質粒子中包含的由前述聚丙烯酸的鹽和前述羧甲基纖維素的鹽中選出的至少一種鹽的以質量作為基準計的含量的合計量，小於前述負極活性物質粒子中包含的前述包含由鎂和鋁中選出的至少一種金屬之金屬鹽的以質量作為基準計的含量的合計量。Furthermore, it is preferable that the total amount of the content on a mass basis of at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose contained in the negative electrode active material particles is smaller than that of the negative electrode. The total amount of the content of the aforementioned metal salt containing at least one metal selected from magnesium and aluminum contained in the active material particles on a mass basis.

若是這種負極活性物質粒子，則能夠更抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，因此更提升水系負極漿料的穩定性。With such negative electrode active material particles, it is possible to further suppress the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles, thereby further improving the stability of the aqueous negative electrode slurry.

又，較佳是：前述負極活性物質粒子包含作為鋰化合物的Li 2Si 2O 5、Li 2SiO 3、Li 4SiO 4中的至少一種以上。 Furthermore, it is preferable that the negative electrode active material particles contain at least one of Li 2 Si 2 O 5 , Li 2 SiO 3 , and Li 4 SiO 4 as a lithium compound.

藉由設為包含作為鋰化合物的如上所述的矽酸鋰，能夠減少在充電時產生的不可逆容量，且能夠提升電池的初次效率和循環特性。By including the lithium silicate as described above as a lithium compound, the irreversible capacity generated during charging can be reduced, and the initial efficiency and cycle characteristics of the battery can be improved.

又，較佳是：前述矽化合物粒子，其根據使用Cu-Kα射線而得的X射線繞射光譜中的由Si(111)結晶面所導致的繞射峰的半值寬(2θ)為1.2°以上，並且，對應於該結晶面之微晶尺寸為7.5 nm以下。Furthermore, it is preferable that the silicon compound particles have a half-value width (2θ) of a diffraction peak due to a Si(111) crystal plane in an X-ray diffraction spectrum obtained by using Cu-Kα rays of 1.2 ° or more, and the crystallite size corresponding to the crystal plane is 7.5 nm or less.

若負極活性物質的矽化合物粒子具有上述矽結晶性，且將該負極活性物質作為鋰離子二次電池的負極活性物質來使用，則能夠獲得更良好的循環特性和起始充放電特性。If the silicon compound particles of the negative electrode active material have the above-mentioned silicon crystallinity, and the negative electrode active material is used as the negative electrode active material of a lithium ion secondary battery, better cycle characteristics and initial charge-discharge characteristics can be obtained.

又，本發明的負極活性物質，較佳是：在前述矽化合物粒子中，由 29Si-魔角旋轉-核磁共振( 29Si-MAS-NMR)波譜所獲得的在作為化學位移值的－60～－95ppm處所呈現的矽和矽酸鋰區域的最大峰強度值A、與在作為化學位移值的－96～－150ppm處所呈現的SiO 2區域的峰強度值B，滿足A＞B的關係。 Further, the negative electrode active material of the present invention, preferred are: in the silicon compound particles in the 29 Si- Magic Angle Spinning - -60 NMR chemical shift values (29 Si-MAS-NMR) spectrum of the obtained The maximum peak intensity value A of the silicon and lithium silicate region appearing at -95 ppm, and the peak intensity value B of the SiO 2 region appearing at -96 to -150 ppm as the chemical shift value, satisfy the relationship of A>B.

在矽化合物粒子中，以SiO 2成分作為基準計，若Si和Li 2SiO 3的量更多時，則能夠成為一種負極活性物質，該負極活性物質能夠充分獲得藉由***鋰來提升電池特性的效果。 Among the silicon compound particles, based on the SiO 2 component, if the amount of Si and Li 2 SiO 3 is larger, it can become a negative electrode active material that can sufficiently improve battery characteristics by inserting lithium Effect.

又，前述負極活性物質粒子，較佳是中值粒徑為3μm以上且15μm以下。In addition, the aforementioned negative electrode active material particles preferably have a median particle diameter of 3 μm or more and 15 μm or less.

若負極活性物質粒子的中值粒徑為3μm以上，則能夠抑制下述情形：由於每單位質量的表面積增加，導致電池不可逆容量增加。另一方面，若將中值粒徑設為15μm以下，則粒子不易碎裂，因此不易出現新生表面。If the median diameter of the negative electrode active material particles is 3 μm or more, it is possible to suppress the increase in the surface area per unit mass, which results in an increase in the irreversible capacity of the battery. On the other hand, if the median particle size is set to 15 μm or less, the particles are less likely to be broken, and therefore, new surfaces are less likely to appear.

又，前述負極活性物質粒子，較佳是在表層部包含碳材料。In addition, the aforementioned negative electrode active material particles preferably contain a carbon material in the surface layer portion.

如此一來，負極活性物質粒子在其表層部包含碳材料，藉此能夠獲得導電性的提升。In this way, the negative electrode active material particles include the carbon material in the surface layer portion thereof, whereby the conductivity can be improved.

又，前述碳材料的平均厚度，較佳是5nm以上且5000nm以下。In addition, the average thickness of the aforementioned carbon material is preferably 5 nm or more and 5000 nm or less.

若碳材料的平均厚度為5nm以上，則能夠獲得導電性的提升。又，若用以被覆的碳材料的平均厚度為5000nm以下，則藉由將包含這種負極活性物質粒子之負極活性物質使用於鋰離子二次電池，能夠確保充分量的矽化合物粒子，因此能夠抑制電池容量下降。If the average thickness of the carbon material is 5 nm or more, the conductivity can be improved. In addition, if the average thickness of the carbon material used for coating is 5000nm or less, by using the negative electrode active material containing such negative electrode active material particles in the lithium ion secondary battery, a sufficient amount of silicon compound particles can be secured, and therefore Suppress the decrease of battery capacity.

又，為了達成上述目的，本發明提供一種混合負極活性物質材料，其特徵在於：包含上述負極活性物質與碳系活性物質。In addition, in order to achieve the above-mentioned object, the present invention provides a mixed negative electrode active material material characterized by comprising the above-mentioned negative electrode active material and a carbon-based active material.

如此一來，作為用以形成負極活性物質層的材料，包含本發明的負極活性物質(矽系負極活性物質)與碳系活性物質，藉此能夠提升負極活性物質層的導電性，並且能夠緩和伴隨充電所引起的膨脹應力。又，藉由將矽系負極活性物質混合至碳系活性物質中，能夠增加電池容量。In this way, as the material for forming the negative electrode active material layer, the negative electrode active material (silicon-based negative electrode active material) of the present invention and the carbon-based active material are included, thereby improving the conductivity of the negative electrode active material layer and reducing With the expansion stress caused by charging. In addition, by mixing the silicon-based negative electrode active material with the carbon-based active material, the battery capacity can be increased.

又，為了達成上述目的，本發明提供一種負極活性物質的製造方法，是製造包含負極活性物質粒子之負極活性物質的方法，該負極活性物質粒子含有矽化合物粒子，該負極活性物質的製造方法的特徵在於，藉由下述步驟來製作負極活性物質粒子：製作矽化合物粒子的步驟，該矽化合物粒子包含矽化合物SiO x，其中，0.5≦x≦1.6；及，對前述矽化合物粒子***鋰來使該矽化合物粒子含有鋰化合物的步驟；並且，包含下述步驟，該步驟使前述負極活性物質粒子包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽、及金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬；然後，使用前述負極活性物質粒子來製造負極活性物質，該負極活性物質粒子包含了前述由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽、及前述金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。 In addition, in order to achieve the above object, the present invention provides a method of manufacturing a negative electrode active material, which is a method of manufacturing a negative electrode active material containing negative electrode active material particles, the negative electrode active material particles containing silicon compound particles, and the method of manufacturing the negative electrode active material It is characterized in that the negative electrode active material particles are produced by the following steps: the step of producing silicon compound particles, the silicon compound particles include silicon compound SiO x , where 0.5≦x≦1.6; and lithium is inserted into the silicon compound particles. The step of making the silicon compound particles contain a lithium compound; and including the step of making the negative electrode active material particles contain at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose, and a metal salt , The metal salt contains at least one metal selected from magnesium and aluminum; then, the negative electrode active material particles are used to produce the negative electrode active material, and the negative electrode active material particles contain the aforementioned salt of polyacrylic acid and carboxymethyl cellulose. At least one salt selected from the salt, and the aforementioned metal salt, the metal salt containing at least one metal selected from magnesium and aluminum.

藉由使負極活性物質粒子包含如上所述的鹽來製造負極活性物質，能夠製造一種負極活性物質，該負極活性物質在製作負極時能夠使所製作的水系負極漿料特別穩定化，並且，在作為鋰離子二次電池的負極活性物質使用時，為高容量且具有良好的循環特性和起始充放電特性。 [發明的功效] By making the negative electrode active material particles contain the salt as described above to produce the negative electrode active material, it is possible to produce a negative electrode active material that can particularly stabilize the produced aqueous negative electrode slurry when the negative electrode is produced, and, When used as a negative electrode active material of a lithium ion secondary battery, it has a high capacity and good cycle characteristics and initial charge-discharge characteristics. [Effect of Invention]

本發明的負極活性物質，在製作負極時能夠使所製作的水系負極漿料特別穩定化，並且，在作為二次電池的負極活性物質來使用時，為高容量且能夠獲得良好的循環特性和起始充放電特性。又，包含此負極活性物質之混合負極活性物質材料，也能夠獲得相同的功效。又，若是本發明的負極活性物質的製造方法，則能夠製造一種負極活性物質，該負極活性物質在製作負極時能夠使所製作的水系漿料特別穩定化，並且，在作為鋰離子二次電池的負極活性物質使用時，具有良好的循環特性和起始充放電特性。The negative electrode active material of the present invention can particularly stabilize the prepared aqueous negative electrode slurry when the negative electrode is produced, and when used as a negative electrode active material of a secondary battery, it has a high capacity and can obtain good cycle characteristics and Initial charge and discharge characteristics. In addition, the mixed negative electrode active material material containing this negative electrode active material can also obtain the same effect. In addition, according to the method for producing a negative electrode active material of the present invention, it is possible to produce a negative electrode active material that can particularly stabilize the produced aqueous slurry when the negative electrode is produced, and is useful as a lithium ion secondary battery When the negative electrode active material is used, it has good cycle characteristics and initial charge-discharge characteristics.

以下，針對本發明說明實施的形態，但本發明並不受限於以下說明。Hereinafter, the embodiments of the present invention will be described, but the present invention is not limited to the following description.

如前所述，作為使鋰離子二次電池的電池容量增加的手法之一，正在研究下述方法：將使用矽材料作爲主要材料之負極，作爲鋰離子二次電池的負極來使用。尤其，摻雜有鋰之矽材料的起始充放電特性和循環特性為良好，但包含這種矽材料之水系負極漿料會有穩定性下降的問題，且尚未提出一種負極活性物質，其具有與使用碳材料之鋰離子二次電池同等的漿料穩定性、起始充放電特性及循環特性。As mentioned above, as one of the methods for increasing the battery capacity of lithium ion secondary batteries, the following method is being studied: using silicon material as the negative electrode of the main material as the negative electrode of the lithium ion secondary battery. In particular, the initial charge-discharge characteristics and cycle characteristics of the silicon material doped with lithium are good, but the aqueous negative electrode slurry containing this silicon material has the problem of reduced stability, and no negative electrode active material has been proposed, which has It has the same slurry stability, initial charge-discharge characteristics and cycle characteristics as lithium-ion secondary batteries using carbon materials.

因此，本發明人為了獲得一種負極活性物質而反覆專心研究，該負極活性物質在使用於二次電池的情況下，為高電池容量且漿料穩定性、循環特性及初次效率良好，從而完成本發明。Therefore, the inventors of the present invention have repeatedly and intensively studied in order to obtain a negative electrode active material that, when used in a secondary battery, has a high battery capacity and good slurry stability, cycle characteristics and initial efficiency, thus completing the present invention. invention.

本發明的負極活性物質，包含負極活性物質粒子。又，此負極活性物質粒子，含有矽化合物粒子，該矽化合物粒子包含矽化合物SiO x，其中，0.5≦x≦1.6；此矽化合物粒子，含有鋰化合物。又，負極活性物質粒子，包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽。進一步，負極活性物質粒子，包含金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。 The negative electrode active material of the present invention includes negative electrode active material particles. In addition, the negative electrode active material particles contain silicon compound particles. The silicon compound particles contain silicon compound SiO x , where 0.5≦x≦1.6; and the silicon compound particles contain a lithium compound. In addition, the negative electrode active material particles include at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose. Furthermore, the negative electrode active material particles include a metal salt, and the metal salt includes at least one metal selected from magnesium and aluminum.

這種負極活性物質，包含負極活性物質粒子(亦稱為矽系活性物質粒子)，該負極活性物質粒子包含矽化合物粒子，因此能夠提升電池容量。又，藉由矽化合物粒子包含鋰化合物，能夠減少在充電時產生的不可逆容量。藉此，能夠提升電池的初次效率和循環特性。又，藉由負極活性物質粒子同時包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽、及金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬，在製作使負極活性物質等分散於水系溶劑中而成之漿料(水系負極漿料)時，能夠抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，而提升水系負極漿料的穩定性。即便負極活性物質粒子僅單獨包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽，也不會提升水系負極漿料的穩定性。又，即便負極活性物質粒子僅單獨包含上述至少一種金屬鹽，提升水系負極漿料的穩定性的功效仍低。This negative electrode active material includes negative electrode active material particles (also referred to as silicon-based active material particles), and the negative electrode active material particles include silicon compound particles, so that the battery capacity can be increased. In addition, since the silicon compound particles contain a lithium compound, it is possible to reduce the irreversible capacity generated during charging. In this way, the initial efficiency and cycle characteristics of the battery can be improved. In addition, since the negative electrode active material particles simultaneously contain at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose, and the metal salt, the metal salt contains at least one metal selected from the group consisting of magnesium and aluminum. When preparing a slurry (aqueous negative electrode slurry) in which the negative electrode active material is dispersed in an aqueous solvent, the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles can be suppressed, and the stability of the aqueous negative electrode slurry can be improved. Even if the negative electrode active material particles alone contain at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose, the stability of the aqueous negative electrode slurry will not be improved. Furthermore, even if the negative electrode active material particles only contain the at least one metal salt described above, the effect of improving the stability of the aqueous negative electrode slurry is still low.

＜非水電解質二次電池用負極＞ 繼而，說明包含本發明的負極活性物質之非水電解質二次電池用負極。第1圖是表示非水電解質二次電池用負極(以下亦稱為「負極」)的構成的一例的剖面圖。 ＜Negative electrode for non-aqueous electrolyte secondary battery＞ Next, the negative electrode for a non-aqueous electrolyte secondary battery containing the negative electrode active material of the present invention will be described. Fig. 1 is a cross-sectional view showing an example of the structure of a negative electrode for a non-aqueous electrolyte secondary battery (hereinafter also referred to as "negative electrode").

[負極的構成] 如第1圖所示，負極10的構成爲，在負極集電體11上具有負極活性物質層12。此負極活性物質層12，可設置於負極集電體11的雙面、或亦可僅設置於負極集電體11的單面。進一步，若是使用了本發明的負極活性物質之負極，則也可無負極集電體11。 [The composition of the negative electrode] As shown in FIG. 1, the negative electrode 10 is configured to have the negative electrode active material layer 12 on the negative electrode current collector 11. The negative electrode active material layer 12 may be provided on both sides of the negative electrode current collector 11 or only on one side of the negative electrode current collector 11. Furthermore, in the case of a negative electrode using the negative electrode active material of the present invention, the negative electrode current collector 11 may not be included.

[負極集電體] 負極集電體11是優異的導電性材料，並且是由機械強度優異的物質所構成。作爲能夠用於負極集電體11的導電性材料，可列舉例如銅(Cu)和鎳(Ni)。此導電性材料，較佳是不會與鋰(Li)形成金屬間化合物的材料。 [Negative Current Collector] The negative electrode current collector 11 is an excellent conductive material, and is composed of a material having excellent mechanical strength. Examples of conductive materials that can be used for the negative electrode current collector 11 include copper (Cu) and nickel (Ni). The conductive material is preferably a material that does not form an intermetallic compound with lithium (Li).

負極集電體11，較佳是：除了主元素以外，還包含碳(C)和硫(S)。原因在於，能夠提升負極集電體的物理強度。尤其，原因在於，當具有在充電時會膨脹的活性物質層時，若集電體包含上述元素，則具有抑制包含集電體之電極發生變形的功效。上述含有元素的含量，並無特別限定，其中，較佳是分別為100質量ppm以下。原因在於，能夠獲得更高的變形抑制功效。藉由這樣的變形抑制功效，能夠更提升循環特性。The negative electrode current collector 11 preferably contains carbon (C) and sulfur (S) in addition to the main element. The reason is that the physical strength of the negative electrode current collector can be improved. In particular, the reason is that when an active material layer that swells during charging is provided, if the current collector contains the above-mentioned elements, it has an effect of suppressing the deformation of the electrode including the current collector. The content of the above-mentioned contained element is not particularly limited, but it is preferably 100 mass ppm or less, respectively. The reason is that a higher deformation suppression effect can be obtained. With this deformation suppression effect, the cycle characteristics can be further improved.

又，負極集電體11的表面可進行粗糙化，也可不進行粗糙化。被粗糙化的負極集電體，例如是經過電解處理、壓紋處理、或化學蝕刻處理的金屬箔等。未被粗糙化的負極集電體，例如是軋延金屬箔等。In addition, the surface of the negative electrode current collector 11 may or may not be roughened. The roughened negative electrode current collector is, for example, a metal foil that has undergone electrolytic treatment, embossing treatment, or chemical etching treatment. The non-roughened negative electrode current collector is, for example, rolled metal foil.

[負極活性物質層] 負極活性物質層12，包含能夠吸留、釋放鋰離子之本發明的負極活性物質，從電池設計上的觀點而言，亦可進一步包含負極黏著劑(黏結劑)或導電助劑等其他材料。負極活性物質包含負極活性物質粒子，該負極活性物質粒子包含含有矽化合物(SiO x：0.5≦x≦1.6)之矽化合物粒子。 [Negative electrode active material layer] The negative electrode active material layer 12 includes the negative electrode active material of the present invention capable of occluding and releasing lithium ions. From the viewpoint of battery design, it may further include a negative electrode binder (binder) or conductive material. Other materials such as additives. The negative electrode active material includes negative electrode active material particles, and the negative electrode active material particles include silicon compound particles containing silicon compounds (SiO x : 0.5≦x≦1.6).

又，負極活性物質層12，可包含混合負極活性物質，該混合負極活性物質包含本發明的負極活性物質與碳系活性物質。藉此，能夠使負極活性物質層的電阻下降，並且緩和伴隨充電所引起的膨脹應力。作為碳系活性物質，可使用例如：熱裂解碳類、焦炭類、玻璃狀碳纖維、有機高分子化合物煅燒體、碳黑類等。In addition, the negative electrode active material layer 12 may include a mixed negative electrode active material containing the negative electrode active material of the present invention and a carbon-based active material. Thereby, the resistance of the negative electrode active material layer can be reduced, and the expansion stress caused by charging can be alleviated. As the carbon-based active material, for example, pyrolysis carbon, coke, glassy carbon fiber, organic polymer compound calcined body, carbon black, etc. can be used.

又，混合負極活性物質材料，較佳是：相對於本發明的負極活性物質(矽系負極活性物質)與碳系活性物質的質量的合計量，矽系負極活性物質的質量比例為6質量%以上。若相對於矽系負極活性物質與碳系活性物質的質量的合計量，矽系負極活性物質的質量比例為6質量%以上，則能夠確實地提升電池容量。In addition, the mixed negative electrode active material material preferably has a mass ratio of the silicon-based negative electrode active material of 6 mass% relative to the total mass of the negative electrode active material (silicon-based negative electrode active material) of the present invention and the carbon-based active material. above. If the mass ratio of the silicon-based negative electrode active material is 6 mass% or more with respect to the total mass of the silicon-based negative electrode active material and the carbon-based active material, the battery capacity can be reliably increased.

又，如上所述，本發明的負極活性物質，包含矽化合物粒子，該矽化合物粒子是含有矽化合物 (SiO x：0.5≦x≦1.6)之氧化矽材料，較佳是x接近1。原因在於，能夠獲得高循環特性。再者，本發明中的矽化合物的組成不一定意指純度100%，可包含微量的雜質元素。 In addition, as described above, the negative electrode active material of the present invention includes silicon compound particles. The silicon compound particles are silicon oxide materials containing silicon compounds (SiO x : 0.5≦x≦1.6), and preferably x is close to 1. The reason is that high cycle characteristics can be obtained. Furthermore, the composition of the silicon compound in the present invention does not necessarily mean that the purity is 100%, and may contain trace amounts of impurity elements.

又，在本發明的負極活性物質中，矽化合物粒子較佳是含有作為鋰化合物的Li 2Si 2O 5、Li 2SiO 3、及Li 4SiO 4中的至少一種以上。這種矽化合物粒子，預先將矽化合物中的於電池充放電時的***鋰或使鋰脫離時會不穩定化的SiO 2成分部分，改質成其他矽酸鋰，因此能夠減少在充電時產生的不可逆容量。 In addition, in the negative electrode active material of the present invention, the silicon compound particles preferably contain at least one of Li 2 Si 2 O 5 , Li 2 SiO 3 , and Li 4 SiO 4 as a lithium compound. In this type of silicon compound particles, the SiO 2 component part of the silicon compound that inserts or destabilizes lithium during battery charging and discharging is modified to other lithium silicate, so it can reduce the generation during charging. The irreversible capacity.

又，藉由Li 2Si 2O 5、Li 2SiO 3及Li 4SiO 4中的至少一種以上存在於矽化合物粒子的塊體內部，能夠提升電池特性，若使2種以上鋰化合物共存時，能夠更提升電池特性。再者，這些矽酸鋰，可利用核磁共振(Nuclear Magnetic Resonance，NMR)與X射線光電子能譜(X-ray photoelectron spectroscopy，XPS)來進行定量。XPS與NMR的測定，可藉由例如以下條件來實行。 XPS ‧裝置：X射線光電子能譜裝置； ‧X射線源：單色化的Al Kα射線； ‧X射線斑點直徑：100μm； ‧Ar離子槍濺射條件：0.5kV／2mm×2mm。 29Si MAS NMR(魔角旋轉核磁共振) ‧裝置：Bruker公司製造的700NMR核磁共振頻譜儀； ‧探針：4mmHR-MAS轉子 50μL； ‧試料旋轉速度：10kHz； ‧測定環境溫度：25℃。 In addition, since at least one of Li 2 Si 2 O 5 , Li 2 SiO 3 and Li 4 SiO 4 is present in the bulk of silicon compound particles, battery characteristics can be improved. If two or more lithium compounds coexist, Can further improve battery characteristics. Furthermore, these lithium silicates can be quantified by nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS). The XPS and NMR measurement can be performed under the following conditions, for example. XPS ‧ Device: X-ray photoelectron spectroscopy device; ‧ X-ray source: monochromatic Al Kα rays; ‧X-ray spot diameter: 100μm; ‧Ar ion gun sputtering conditions: 0.5kV/2mm×2mm. 29 Si MAS NMR (Magic Angle Spinning Nuclear Magnetic Resonance) ‧Device: 700NMR NMR spectrometer manufactured by Bruker; ‧Probe: 4mmHR-MAS rotor 50μL; ‧Sample rotation speed: 10kHz; ‧Measurement environment temperature: 25℃.

又，如上所述，本發明的負極活性物質，包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽，進一步亦包含金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。此時，在本發明的負極活性物質中，較佳是：相對於負極活性物質粒子的總量，由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽的總量，在0.1質量%以上且5質量%以下的範圍內。例如，當負極活性物質粒子包含2種以上的由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的鹽時，較佳是：相對於負極活性物質粒子的總量，該2種以上的鹽的質量的合計量為0.1質量%以上且5質量%以下。又，當僅包含1種上述鹽時，較佳是：相對於負極活性物質粒子的質量，該鹽的質量為0.1質量%以上且5質量%以下。如此一來，藉由上述鹽的總量相對於負極活性物質粒子的總量，在0.1質量%以上的範圍內，能夠更充分地抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，而進一步提升水系負極漿料的穩定性。又，若上述鹽的總量相對於負極活性物質粒子的總量，在5質量%以下的範圍內，則電池容量不會下降。In addition, as described above, the negative electrode active material of the present invention contains at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose, and further contains a metal salt, and the metal salt includes a salt selected from magnesium and aluminum. Of at least one metal. At this time, in the negative electrode active material of the present invention, it is preferable that the total amount of at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose relative to the total amount of the negative electrode active material particles is Within the range of 0.1% by mass or more and 5% by mass or less. For example, when the negative electrode active material particles contain two or more kinds of salts selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose, it is preferable that the two or more kinds of salts are relative to the total amount of the negative electrode active material particles. The total amount of the mass of the salt is 0.1% by mass or more and 5% by mass or less. Moreover, when only one kind of the above-mentioned salt is included, it is preferable that the mass of the salt is 0.1% by mass or more and 5% by mass or less with respect to the mass of the negative electrode active material particles. In this way, when the total amount of the salt is in the range of 0.1% by mass or more with respect to the total amount of the negative electrode active material particles, it is possible to more sufficiently suppress the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles, and Further improve the stability of the aqueous negative electrode slurry. In addition, if the total amount of the above-mentioned salt is within a range of 5% by mass or less with respect to the total amount of the negative electrode active material particles, the battery capacity will not decrease.

又，在本發明的負極活性物質中，較佳是：相對於負極活性物質粒子的總量，包含由鎂和鋁中選出的至少一種金屬之金屬鹽的總量，在0.1質量%以上且5質量%以下的範圍內。與上述同樣地，當負極活性物質粒子包含2種以上金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬時，較佳是：相對於負極活性物質粒子的總量，2種以上金屬鹽的質量的合計量為0.1質量%以上且5質量%以下。又，當僅包含1種金屬鹽時，較佳是：相對於負極活性物質粒子的質量，該金屬鹽的質量為0.1質量%以上且5質量%以下。如此一來，藉由金屬鹽的總量相對於負極活性物質粒子的總量在0.1質量%以上的範圍內，能夠更充分地抑制自負極活性物質粒子中的鋰化合物溶析出鋰離子，而進一步提升水系負極漿料的穩定性。又，若金屬鹽的總量相對於負極活性物質粒子的總量在5質量%以下的範圍內，則電池容量不會下降。In addition, in the negative electrode active material of the present invention, it is preferable that the total amount of metal salt containing at least one metal selected from magnesium and aluminum relative to the total amount of negative electrode active material particles is 0.1% by mass or more and 5 Within the range of mass% or less. In the same way as above, when the negative electrode active material particles contain two or more metal salts, and the metal salt contains at least one metal selected from magnesium and aluminum, it is preferred that: relative to the total amount of the negative electrode active material particles, two or more types The total amount of the mass of the metal salt is 0.1% by mass or more and 5% by mass or less. Furthermore, when only one type of metal salt is included, it is preferable that the mass of the metal salt is 0.1% by mass or more and 5% by mass or less with respect to the mass of the negative electrode active material particles. In this way, when the total amount of the metal salt is in the range of 0.1% by mass or more with respect to the total amount of the negative electrode active material particles, it is possible to more sufficiently suppress the elution and precipitation of lithium ions from the lithium compound in the negative electrode active material particles, and further Improve the stability of aqueous anode slurry. In addition, if the total amount of the metal salt is within a range of 5% by mass or less with respect to the total amount of the negative electrode active material particles, the battery capacity will not decrease.

又，尤其在本發明中，較佳是：負極活性物質粒子中包含的由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽的以質量作為基準計的含量的合計量，小於負極活性物質粒子中包含的金屬鹽的以質量作為基準計的含量的合計量，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。藉由包含比聚丙烯酸的鹽等更多的金屬鹽，能夠更提升水系負極漿料的穩定性。In addition, in the present invention, it is preferable that the total amount of the content of at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose contained in the negative electrode active material particles on a mass basis, It is less than the total amount of the content based on mass of the metal salt contained in the negative electrode active material particles, and the metal salt contains at least one metal selected from magnesium and aluminum. By containing more metal salt than the salt of polyacrylic acid, the stability of the aqueous negative electrode slurry can be improved.

又，在本發明中，作為聚丙烯酸的鹽或羧甲基纖維素的鹽，可由下述鹽選擇至少一種：羧甲基纖維素的銨鹽(CMC-NH 4)、聚丙烯酸的鋰鹽(PAA-Li)、及聚丙烯酸的銨鹽(PAA-NH 4)等。其中，尤其，較佳是聚丙烯酸的鹽或羧甲基纖維素的鹽是銨鹽。原因在於，若是這種鹽，則能夠更提升水系負極漿料的穩定性。 In the present invention, as the salt of polyacrylic acid or the salt of carboxymethyl cellulose, at least one of the following salts can be selected: ammonium salt of carboxymethyl cellulose (CMC-NH 4 ), lithium salt of polyacrylic acid ( PAA-Li), and the ammonium salt of polyacrylic acid (PAA-NH 4 ), etc. Among them, it is particularly preferable that the salt of polyacrylic acid or the salt of carboxymethyl cellulose is an ammonium salt. The reason is that if it is such a salt, the stability of the aqueous negative electrode slurry can be further improved.

又，在本發明中，較佳是包含由鎂和鋁中選出的至少一種金屬之金屬鹽是硝酸鹽、磷酸鹽、鹽酸鹽及硫酸鹽中的任一種。原因在於，若包含這種金屬鹽，則能夠更提升水系負極漿料的穩定性。更具體而言，作為包含由鎂和鋁中選出的至少一種金屬之金屬鹽，可由下述鹽選擇至少一種金屬鹽：Mg(NO 3) 2、MgCl 2、MgSO 4、Mg 3(PO 4) 2、AlCl 3、Al(NO 3) 3、及AlPO 4等。 Furthermore, in the present invention, it is preferable that the metal salt containing at least one metal selected from magnesium and aluminum is any one of nitrate, phosphate, hydrochloride, and sulfate. The reason is that if such a metal salt is contained, the stability of the aqueous negative electrode slurry can be further improved. More specifically, as the metal salt containing at least one metal selected from magnesium and aluminum, at least one metal salt can be selected from the following salts: Mg(NO 3 ) 2 , MgCl 2 , MgSO 4 , Mg 3 (PO 4 ) 2. AlCl 3 , Al(NO 3 ) 3 , and AlPO 4 etc.

又，聚丙烯酸的鹽或羧甲基纖維素的鹽、及包含由鎂和鋁中選出的至少一種金屬之金屬鹽，較佳是弱鹼性。若使用弱鹼性鹽，相較於使用酸性鹽的情況，更不易自矽酸鋰溶析出鋰。In addition, the salt of polyacrylic acid or the salt of carboxymethyl cellulose, and the metal salt containing at least one metal selected from magnesium and aluminum are preferably weakly alkaline. If a weakly basic salt is used, it is more difficult to dissolve out lithium from lithium silicate than when an acid salt is used.

又，矽化合物粒子，較佳是：藉由使用Cu-Kα射線而實行的X射線繞射所獲得的由Si(111)結晶面所導致的繞射峰的半值寬(2θ)為1.2°以上，並且，對應於該結晶面的微晶尺寸為7.5 nm以下。此峰，在結晶性較高時(半值寬較狹窄時)出現於2θ＝28.4±0.5°附近。矽化合物粒子中的矽化合物的矽結晶性愈低愈佳，尤其，若矽晶體的存在量較少，則能夠提升電池特性，進一步能夠生成穩定的鋰化合物。In addition, the silicon compound particles preferably have a half-value width (2θ) of the diffraction peak due to the Si(111) crystal plane obtained by X-ray diffraction using Cu-Kα rays of 1.2° In addition, the crystallite size corresponding to the crystal plane is 7.5 nm or less. This peak appears near 2θ=28.4±0.5° when the crystallinity is high (when the half-value width is narrow). The lower the silicon crystallinity of the silicon compound in the silicon compound particles, the better. In particular, if the amount of silicon crystals is small, the battery characteristics can be improved, and a stable lithium compound can be further generated.

又，本發明的負極活性物質，較佳是：在矽化合物粒子中，由 29Si-MAS-NMR波譜所獲得的在作為化學位移值的－60～－95ppm處所呈現的矽與矽酸鋰區域的最大峰強度值A、與在作為化學位移值的－96～－150ppm處所呈現的SiO 2區域的峰強度值B，滿足A＞B的關係。在矽化合物粒子中，當以SiO 2成分作為基準時，若矽成分或Li 2SiO 3的量相對較多，則能夠充分獲得藉由***鋰來提升電池特性的功效。再者， 29Si-MAS-NMR的測定條件可與上述相同。 In addition, the negative electrode active material of the present invention is preferably: in the silicon compound particles, a region of silicon and lithium silicate exhibited at -60 to -95 ppm as a chemical shift value obtained from 29 Si-MAS-NMR spectrum The maximum peak intensity value of A and the peak intensity value B of the SiO 2 region appearing at -96 to -150 ppm as the chemical shift value satisfy the relationship of A>B. In the silicon compound particles, when the SiO 2 component is used as a reference, if the amount of the silicon component or Li 2 SiO 3 is relatively large, the effect of improving the battery characteristics by inserting lithium can be sufficiently obtained. In addition, the measurement conditions of 29 Si-MAS-NMR may be the same as described above.

又，較佳是負極活性物質粒子的中值粒徑(D 50：累積體積為50%時的粒徑)為3μm以上且15μm以下。原因在於，若中值粒徑在上述範圍內，則在充放電時容易吸留、釋放鋰離子，並且粒子不易碎裂。若中值粒徑為3μm以上，則能夠縮小每單位質量的表面積，而能夠抑制電池不可逆容量增加。另一方面，若將中值粒徑設為15μm以下，則使粒子不易碎裂，因此不易出現新生表面。 Moreover, it is preferable that the median diameter (D 50 : the particle diameter when the cumulative volume is 50%) of the negative electrode active material particles is 3 μm or more and 15 μm or less. The reason is that if the median particle size is within the above range, lithium ions are easily occluded and released during charge and discharge, and the particles are not easily broken. If the median particle size is 3 μm or more, the surface area per unit mass can be reduced, and the irreversible capacity increase of the battery can be suppressed. On the other hand, if the median particle size is set to 15 μm or less, the particles are not easily broken, and therefore, a new surface is not likely to appear.

又，在本發明的負極活性物質中，負極活性物質粒子，較佳是在表層部包含碳材料。藉由負極活性物質在其表層部包含碳材料，能夠獲得導電性的提升，因此，在將包含這種負極活性物質粒子之負極活性物質作為二次電池的負極活性物質使用時，能夠提升電池特性。In addition, in the negative electrode active material of the present invention, the negative electrode active material particles preferably contain a carbon material in the surface layer portion. When the negative electrode active material contains a carbon material in its surface layer, the conductivity can be improved. Therefore, when the negative electrode active material containing such negative electrode active material particles is used as the negative electrode active material of the secondary battery, the battery characteristics can be improved .

又，負極活性物質粒子的表層部的碳材料的平均厚度，較佳是5nm以上且5000nm以下。若碳材料的平均厚度為5nm以上，則能夠獲得導電性的提升；若所被覆的碳材料的平均厚度為5000nm以下，則在將包含這種負極活性物質粒子之負極活性物質作為二次電池的負極活性物質使用時，能夠抑制電池容量下降。In addition, the average thickness of the carbon material in the surface layer portion of the negative electrode active material particle is preferably 5 nm or more and 5000 nm or less. If the average thickness of the carbon material is 5nm or more, the conductivity can be improved; if the average thickness of the coated carbon material is 5000nm or less, the negative electrode active material containing this negative electrode active material particle is used as the secondary battery When the negative electrode active material is used, it is possible to suppress the decrease in battery capacity.

此碳材料的平均厚度，可根據例如以下程序來計算。首先，藉由TEM(穿透式電子顯微鏡)以任意倍率來觀察負極活性物質粒子。此倍率較佳是下述倍率：以能夠測定厚度的方式，能夠利用目視確認碳材料的厚度的倍率。繼而，在任意15點測定碳材料的厚度。此時，較佳是：盡可能不集中在特定處，廣泛且隨機地設定測定位置。最後，計算出上述15點的碳材料的厚度的平均值。The average thickness of this carbon material can be calculated according to the following procedure, for example. First, the negative electrode active material particles are observed at an arbitrary magnification by TEM (transmission electron microscope). This magnification is preferably a magnification at which the thickness of the carbon material can be visually confirmed so that the thickness can be measured. Then, the thickness of the carbon material was measured at 15 arbitrary points. In this case, it is preferable not to concentrate on a specific place as much as possible, and to set the measurement position widely and randomly. Finally, the average value of the thickness of the carbon material at the above 15 points is calculated.

碳材料的被覆率，並無特別限定，較理想是盡可能高。若被覆率為30%以上，則能夠更提升導電性，因此較佳。碳材料的被覆方法，並無特別限定，較佳是糖碳化法、烴氣的熱裂解法。原因在於，能夠提升被覆率。The coverage rate of the carbon material is not particularly limited, but it is preferably as high as possible. If the coverage rate is 30% or more, the conductivity can be further improved, which is preferable. The coating method of the carbon material is not particularly limited, but a sugar carbonization method or a thermal cracking method of hydrocarbon gas is preferable. The reason is that the coverage rate can be improved.

作為負極活性物質層中包含的負極黏著劑，可使用例如：高分子材料、合成橡膠等任一種以上。高分子材料，例如是：聚偏氟乙烯、聚醯亞胺、聚醯胺醯亞胺、芳綸、聚丙烯酸、聚丙烯酸鋰、羧甲基纖維素等。合成橡膠，例如是：苯乙烯丁二烯系橡膠、氟系橡膠、乙烯丙烯二烯等。As the negative electrode binder contained in the negative electrode active material layer, for example, any one or more of polymer materials, synthetic rubber, and the like can be used. The polymer material is, for example, polyvinylidene fluoride, polyimide, polyimide, aramid, polyacrylic acid, lithium polyacrylate, carboxymethyl cellulose, and the like. Synthetic rubbers are, for example, styrene butadiene rubber, fluorine rubber, ethylene propylene diene, and the like.

作為負極導電助劑，可使用例如：碳黑、乙炔黑、石墨、科琴黑、碳奈米管、及碳奈米纖維等碳材料的任一種以上。As the negative electrode conductive assistant, for example, any one or more of carbon materials such as carbon black, acetylene black, graphite, Ketjen black, carbon nanotube, and carbon nanofiber can be used.

負極活性物質層，是利用例如塗佈法來形成。塗佈法是指下述方法：將負極活性物質粒子與上述黏著劑等，根據需要而與導電助劑、碳材料混合後，使其分散於有機溶劑或水等中，並進行塗佈。The negative electrode active material layer is formed by, for example, a coating method. The coating method refers to a method of mixing the negative electrode active material particles with the above-mentioned binder, etc., with a conductive auxiliary agent and a carbon material as necessary, and then dispersing the particles in an organic solvent, water, etc., and then coating.

[負極的製造方法] 負極，可根據例如以下程序來製造。首先，說明使用於負極的負極活性物質的製造方法。一開始先製作包含矽化合物(SiO x：0.5≦x≦1.6)之矽化合物粒子。繼而，對矽化合物粒子***鋰來使該矽化合物粒子含有鋰化合物。以這樣的方式進行，來製作負極活性物質粒子。繼而，使所製作的負極活性物質粒子包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽、及金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。然後，使用此負極活性物質粒子來製造負極活性物質。 [Method of Manufacturing Negative Electrode] The negative electrode can be manufactured according to, for example, the following procedure. First, the method of manufacturing the negative electrode active material used in the negative electrode will be described. At the beginning, silicon compound particles containing silicon compound (SiO x : 0.5≦x≦1.6) are produced. Then, lithium is inserted into the silicon compound particles so that the silicon compound particles contain the lithium compound. In this way, negative electrode active material particles are produced. Next, the produced negative electrode active material particles are made to contain at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose, and a metal salt, and the metal salt contains at least one metal selected from magnesium and aluminum. Then, the negative electrode active material particles are used to produce a negative electrode active material.

更具體而言，能以下述方式來製造負極活性物質。首先，在惰性氣體的存在下、減壓下，以900℃〜1600℃的溫度範圍內的溫度，對能夠産生氧化矽氣體的原料進行加熱，來使氧化矽氣體產生。考慮到金屬矽粉末的表面氧和反應爐中的微量氧的存在，較理想是混合莫耳比在0.8＜金屬矽粉末/二氧化矽粉末＜1.3的範圍內。More specifically, the negative electrode active material can be produced in the following manner. First, in the presence of an inert gas and under reduced pressure, a raw material capable of generating silicon oxide gas is heated at a temperature within a temperature range of 900° C. to 1600° C. to generate silicon oxide gas. Taking into account the presence of surface oxygen of the metallic silicon powder and trace oxygen in the reaction furnace, it is more desirable that the mixed molar ratio is in the range of 0.8<metallic silicon powder/silicon dioxide powder<1.3.

所產生的氧化矽氣體在吸附板上固體化並沉積。繼而，在將反應爐內溫度降低到100℃以下的狀態下，取出氧化矽的沉積物，並使用球磨機、氣流粉碎機等來進行粉碎，來實行粉末化。可對以這樣的方式進行來獲得的粉末進行分級。在本發明中，能夠於粉碎步驟和分級步驟時調整矽化合物粒子的粒度分布。能以上述方式進行，來製作矽化合物粒子。再者，矽化合物粒子中的矽微晶，能以藉由汽化溫度的變更或生成後的熱處理來加以控制。The generated silicon oxide gas is solidified and deposited on the adsorption plate. Then, in a state where the temperature in the reaction furnace is lowered to 100°C or less, the silica deposits are taken out, and pulverized using a ball mill, jet mill, etc., to pulverize. The powder obtained in this manner can be classified. In the present invention, the particle size distribution of the silicon compound particles can be adjusted during the pulverization step and the classification step. This can be done in the above manner to produce silicon compound particles. Furthermore, the silicon crystallites in the silicon compound particles can be controlled by the change of the vaporization temperature or the heat treatment after the formation.

此處，可在矽化合物粒子的表層生成碳材料層。作為生成碳材料層的方法，較理想是熱裂解化學氣相沉積法(熱裂解CVD法)。針對利用熱裂解CVD法來生成碳材料層的方法進行說明。Here, a carbon material layer can be formed on the surface layer of the silicon compound particles. As a method of forming the carbon material layer, a thermal cracking chemical vapor deposition method (thermal cracking CVD method) is preferable. The method of forming the carbon material layer by the thermal pyrolysis CVD method will be described.

首先，將矽化合物粒子裝入爐內。繼而，對爐內導入烴氣，並使爐內溫度升溫。分解溫度，並無特別限定，較理想是1200℃以下，更理想是950℃以下。藉由將分解溫度設成1200℃以下，能夠抑制活性物質粒子的意料外的歧化。使爐內溫度上升至特定溫度為止後，在矽化合物粒子的表面形成碳層。又，作為碳材料的原料之烴氣，並無特別限定，較理想是在C nH m組成中，n≦3。若n≦3，則能夠降低製造成本，並且能夠使分解生成物的物性良好。 First, the silicon compound particles are charged into the furnace. Then, a hydrocarbon gas is introduced into the furnace, and the temperature in the furnace is raised. The decomposition temperature is not particularly limited, but it is preferably 1200°C or lower, and more preferably 950°C or lower. By setting the decomposition temperature to 1200°C or lower, unexpected disproportionation of the active material particles can be suppressed. After raising the temperature in the furnace to a specific temperature, a carbon layer is formed on the surface of the silicon compound particles. In addition, the hydrocarbon gas used as the raw material of the carbon material is not particularly limited, and it is preferable that in the C n H m composition, n≦3. If n≦3, the manufacturing cost can be reduced, and the physical properties of the decomposition product can be improved.

繼而，對以上述方式製作的矽活性物質粒子***鋰，來使該矽活性物質粒子含有鋰化合物。此時，較佳是含有作為鋰化合物的Li 2Si 2O 5、Li 2SiO 3、Li 4SiO 4中的至少一種以上。為了獲得這樣的矽酸鋰，鋰的***，較佳是藉由氧化還原法來實行。 Then, lithium is inserted into the silicon active material particles produced as described above, so that the silicon active material particles contain a lithium compound. In this case, it is preferable to contain at least one of Li 2 Si 2 O 5 , Li 2 SiO 3 , and Li 4 SiO 4 as the lithium compound. In order to obtain such lithium silicate, the insertion of lithium is preferably performed by an oxidation-reduction method.

在藉由氧化還原法來實行的改質中，例如，首先，將矽活性物質粒子浸泡在將鋰溶於醚溶劑而得之溶液A中，藉此能夠***鋰。可使此溶液A中進一步含有多環芳香族化合物或直鏈聚伸苯化合物。***鋰後，將矽活性物質粒子浸泡在包含多環芳香族化合物或其衍生物之溶液B中，藉此能夠將活性鋰自矽活性物質粒子脫離。此溶液B的溶劑，可使用例如：醚系溶劑、酮系溶劑、酯系溶劑、醇系溶劑、胺系溶劑、或這些溶劑的混合溶劑。或者，在浸泡於溶液A後，可在400～800℃的非活性氣體下對所獲得的矽活性物質粒子進行熱處理。藉由進行熱處理，能夠使鋰化合物穩定化。之後，可利用下述方法來進行清洗：利用醇、溶有碳酸鋰之鹼性水、弱酸或純水等進行清洗。In the modification performed by the oxidation-reduction method, for example, first, the silicon active material particles are immersed in the solution A obtained by dissolving lithium in an ether solvent, so that lithium can be inserted. The solution A may further contain a polycyclic aromatic compound or a linear polyphenylene compound. After the lithium is inserted, the silicon active material particles are immersed in the solution B containing the polycyclic aromatic compound or its derivatives, so that the active lithium can be separated from the silicon active material particles. As the solvent of this solution B, for example, ether solvents, ketone solvents, ester solvents, alcohol solvents, amine solvents, or mixed solvents of these solvents can be used. Alternatively, after immersing in the solution A, the obtained silicon active material particles may be heat-treated under an inert gas at 400-800°C. The heat treatment can stabilize the lithium compound. After that, the following method can be used for cleaning: using alcohol, alkaline water with lithium carbonate dissolved, weak acid or pure water, etc. for cleaning.

作為用於溶液A的醚系溶劑，可使用：二乙基醚、三級丁基甲基醚、四氫呋喃、二噁烷、1,2-二甲氧基乙烷、二乙二醇二甲基醚、三乙二醇二甲基醚、四乙二醇二甲基醚、或這些溶劑的混合溶劑等。其中，尤其，較佳是使用四氫呋喃、二噁烷、1,2-二甲氧基乙烷。這些溶劑，較佳是已被脫水，較佳是已被脫氧。As the ether solvent used in the solution A, diethyl ether, tertiary butyl methyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, Triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, or a mixed solvent of these solvents, etc. Among them, it is particularly preferable to use tetrahydrofuran, dioxane, and 1,2-dimethoxyethane. These solvents are preferably dehydrated, and preferably deoxygenated.

作為溶液A中包含的多環芳香族化合物，可使用：萘、蒽、菲、稠四苯、稠五苯、芘(pyrene)、苉(picene)、聯伸三苯(triphenylene)、蔻(coronene)、䓛(chrysene)及這些多環芳香族化合物的衍生物中的1種以上；作為直鏈聚伸苯化合物，可使用：聯苯、聯三苯(terphenyl)及這些直鏈聚伸苯化合物的衍生物中的1種以上。As the polycyclic aromatic compound contained in the solution A, naphthalene, anthracene, phenanthrene, fused tetrabenzene, fused pentacene, pyrene, picene, triphenylene, coronene can be used , Chrysene and at least one of the derivatives of these polycyclic aromatic compounds; as linear polyphenylene compounds, you can use: biphenyl, terphenyl and these linear polyphenylene compounds One or more of derivatives.

作為溶液B中包含的多環芳香族化合物，可使用：萘、蒽、菲、稠四苯、稠五苯、芘、苉、聯伸三苯、蔻、䓛及這些多環芳香族化合物的衍生物中的1種以上。As the polycyclic aromatic compound contained in the solution B, naphthalene, anthracene, phenanthrene, fused tetrabenzene, fused pentacene, pyrene, acenamon, triphenylene, coronene, chrysene, and derivatives of these polycyclic aromatic compounds can be used One or more of them.

作為溶液B的醚系溶劑，可使用：二乙基醚、三級丁基甲基醚、四氫呋喃、二噁烷、1,2-二甲氧基乙烷、二乙二醇二甲基醚、三乙二醇二甲基醚、及四乙二醇二甲基醚等。As the ether solvent of solution B, you can use: diethyl ether, tertiary butyl methyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, triethyl Glycol dimethyl ether, and tetraethylene glycol dimethyl ether, etc.

作為酮系溶劑，可使用丙酮、苯乙酮等。As the ketone solvent, acetone, acetophenone, etc. can be used.

作為酯系溶劑，可使用：甲酸甲酯、乙酸甲酯、乙酸乙酯、乙酸丙酯、及乙酸異丙酯等。As the ester solvent, methyl formate, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, and the like can be used.

作為醇系溶劑，可使用：甲醇、乙醇、丙醇、及異丙醇等。As the alcohol solvent, methanol, ethanol, propanol, isopropanol, etc. can be used.

作為胺系溶劑，可使用：甲胺、乙胺、及乙二胺等。As the amine solvent, methylamine, ethylamine, ethylenediamine, etc. can be used.

除此之外，可藉由熱摻雜法來對矽活性物質粒子***鋰。在藉由熱摻雜法進行的改質中，可藉由例如下述方式進行改質：將矽活性物質粒子與氫化鋰粉末或鋰粉混合，且在非氧化氣氛下進行加熱。作為非氧化氣氛，可使用例如氬(Ar)氣氛等。更具體而言，首先，在Ar氣氛下將氫化鋰粉末或鋰粉末與氧化矽粉末充分混合，並實行密封，然後將密封後的容器整個進行攪拌，藉此均勻化。之後，以700℃～750℃的範圍內的溫度進行加熱，來實行改質。又，此時，要將鋰自矽化合物脫離，可將加熱後的粉末充分冷卻，之後利用醇類或鹼性水、弱酸或純水來進行清洗。In addition, the thermal doping method can be used to insert lithium into the silicon active material particles. In the modification by the thermal doping method, the modification can be carried out by, for example, mixing silicon active material particles with lithium hydride powder or lithium powder, and heating in a non-oxidizing atmosphere. As the non-oxidizing atmosphere, for example, an argon (Ar) atmosphere or the like can be used. More specifically, first, the lithium hydride powder or the lithium powder and the silicon oxide powder are thoroughly mixed in an Ar atmosphere and sealed, and then the entire sealed container is stirred for homogenization. After that, heating is performed at a temperature in the range of 700°C to 750°C to perform modification. In addition, at this time, to release lithium from the silicon compound, the heated powder can be sufficiently cooled, and then washed with alcohol, alkaline water, weak acid, or pure water.

再者，當根據熱摻雜法實行改質時，由矽化合物粒子所獲得的 29Si-MAS-NMR波譜，與使用氧化還原法的情況不同。第2圖中表示當根據氧化還原法實行改質後由矽化合物粒子測定出來的 29Si-MAS-NMR波譜的一例。在第2圖中，－75ppm處附近呈現的峰為源自Li 2SiO 3的峰，－80～－100ppm處呈現的峰為源自矽的峰。再者，至－80～－100ppm為止，亦有時具有除了Li 2SiO 3、Li 4SiO 4以外的矽酸鋰的峰。 Furthermore, when the modification is performed according to the thermal doping method, the 29 Si-MAS-NMR spectrum obtained from the silicon compound particles is different from the case of using the redox method. Figure 2 shows an example of the 29 Si-MAS-NMR spectrum measured from silicon compound particles after modification according to the oxidation-reduction method. In Figure 2, the peaks appearing near -75 ppm are peaks derived from Li 2 SiO 3 , and the peaks appearing at -80 to -100 ppm are peaks derived from silicon. In addition, it may have peaks of lithium silicate other than Li 2 SiO 3 and Li 4 SiO 4 up to -80 to -100 ppm.

又，第3圖表示當根據熱摻雜法實行改質後由矽化合物粒子測定出來的 29Si-MAS-NMR波譜的一例。在第3圖中，－75ppm處附近呈現的峰為源自Li 2SiO 3的峰，－80～－100ppm處呈現的峰為源自矽的峰。再者，至－80～－100ppm為止，亦有時具有除了Li 2SiO 3、Li 4SiO 4以外的矽酸鋰的峰。再者，可由XPS波譜確認Li 4SiO 4的峰。 In addition, Fig. 3 shows an example of 29 Si-MAS-NMR spectrum measured from silicon compound particles after modification by the thermal doping method. In Figure 3, the peak appearing near -75 ppm is a peak derived from Li 2 SiO 3 , and the peak appearing at -80 to -100 ppm is a peak derived from silicon. In addition, it may have peaks of lithium silicate other than Li 2 SiO 3 and Li 4 SiO 4 up to -80 to -100 ppm. Furthermore, the peak of Li 4 SiO 4 can be confirmed by XPS spectrum.

繼而，使所製作的負極活性物質粒子包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽、及金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬。要使負極活性物質粒子包含這些鹽，可使用如下所述的方法。Next, the produced negative electrode active material particles are made to contain at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose, and a metal salt, and the metal salt contains at least one metal selected from magnesium and aluminum. To make the negative electrode active material particles contain these salts, the method described below can be used.

例如，可使用如下所述的濕式混合法。在濕式混合法中，能夠藉由下述方式來使負極活性物質粒子的表面包含上述鹽：將分散有由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽與包含由鎂和鋁中選出的至少一種金屬之金屬鹽之溶液，噴霧在負極活性物質粒子的表面，並在噴霧後使負極活性物質粒子乾燥。For example, a wet mixing method as described below can be used. In the wet mixing method, the surface of the negative electrode active material particles can be made to contain the above-mentioned salt by dispersing at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose and containing A solution of a metal salt of at least one metal selected from magnesium and aluminum is sprayed on the surface of the negative electrode active material particles, and the negative electrode active material particles are dried after spraying.

更具體而言，例如，能夠將在水系溶劑中分散有聚丙烯酸的鹽與磷酸鋁而成之水溶液，噴霧在負極活性物質粒子上，並使負極活性物質粒子乾燥。雖然聚丙烯酸的鹽溶於水系溶劑中，但磷酸鋁不溶於水系溶劑中，因此在水系溶劑中的這些鹽之間幾乎不會產生陽離子或陰離子交換。因此，當分散於溶劑中時，能夠根據負極活性物質粒子的質量而調整上述各種鹽的質量，來調節負極活性物質粒子中的各種鹽的濃度。又，除此之外，亦可將分散有羧甲基纖維素的鹽與金屬鹽之乙醇等有機溶劑，噴霧在負極活性物質粒子上，並使負極活性物質粒子乾燥。More specifically, for example, an aqueous solution in which a salt of polyacrylic acid and aluminum phosphate are dispersed in an aqueous solvent can be sprayed on the negative electrode active material particles, and the negative electrode active material particles can be dried. Although the salt of polyacrylic acid is soluble in the aqueous solvent, the aluminum phosphate is insoluble in the aqueous solvent, so there is almost no cation or anion exchange between these salts in the aqueous solvent. Therefore, when dispersed in a solvent, the masses of the various salts described above can be adjusted according to the mass of the negative electrode active material particles to adjust the concentration of the various salts in the negative electrode active material particles. In addition, an organic solvent such as ethanol in which a salt of carboxymethyl cellulose and a metal salt are dispersed may be sprayed on the negative electrode active material particles, and the negative electrode active material particles may be dried.

又，除了如上所述的濕式混合法以外，亦可使用乾式混合法。此時，能夠藉由使用公知的處理裝置(Hosokawa Micron NOBILTA(R) NOB、Hosokawa Micron NAUTA MIXER(R) DBX等)，來對負極活性物質粒子、由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽、及包含由鎂和鋁中選出的至少一種金屬之金屬鹽進行乾式混合，使上述各種鹽附著於負極活性物質粒子的表面。In addition to the wet mixing method described above, a dry mixing method may also be used. At this time, by using a well-known processing device (Hosokawa Micron NOBILTA(R) NOB, Hosokawa Micron NAUTA MIXER(R) DBX, etc.), the negative electrode active material particles, the At least one salt selected from the salt and a metal salt containing at least one metal selected from magnesium and aluminum are dry-mixed to allow the various salts to adhere to the surface of the negative electrode active material particles.

將以上述方式製作的負極活性物質，與負極黏著劑、導電助劑等其他材料混合，來作成負極混合劑後，加入有機溶劑或水等，來作成漿料。繼而，對負極集電體的表面，塗佈上述漿料，並使其乾燥，來形成負極活性物質層。此時，亦可根據需要而實行熱壓等。以上述方式進行，可製作負極。The negative electrode active material prepared in the above manner is mixed with other materials such as a negative electrode adhesive, a conductive auxiliary agent, etc. to form a negative electrode mixture, and then an organic solvent or water is added to form a slurry. Then, the above-mentioned slurry is applied to the surface of the negative electrode current collector and dried to form a negative electrode active material layer. At this time, hot pressing or the like may be performed as needed. In the above manner, a negative electrode can be produced.

＜鋰離子二次電池＞ 繼而，說明包含本發明的負極活性物質之鋰離子二次電池。此處，作為具體例，可列舉層合薄膜型鋰離子二次電池為例子。 ＜Lithium ion secondary battery＞ Next, a lithium ion secondary battery containing the negative electrode active material of the present invention will be described. Here, as a specific example, a laminated thin film type lithium ion secondary battery can be cited as an example.

[層合薄膜型鋰離子二次電池的構成] 如第4圖所示之層合薄膜型鋰離子二次電池20，主要在片狀的外裝構件25的內部收納有捲繞電極體21。此捲繞電極體，是在正極、負極之間具有隔板，並捲繞而成。又，亦存在有下述情況：在正極、負極之間具有隔板並收納有積層體。在任一電極體中，正極上安裝有正極引線22，負極上安裝有負極引線23。電極體的最外周部，是由保護膠帶所保護。 [Constitution of laminated film type lithium ion secondary battery] The laminated thin-film type lithium ion secondary battery 20 shown in FIG. 4 mainly houses a wound electrode body 21 inside a sheet-shaped exterior member 25. This wound electrode body is formed by winding it with a separator between the positive electrode and the negative electrode. In addition, there are also cases where a separator is provided between the positive electrode and the negative electrode, and the laminate is accommodated. In either electrode body, a positive electrode lead 22 is mounted on the positive electrode, and a negative electrode lead 23 is mounted on the negative electrode. The outermost periphery of the electrode body is protected by a protective tape.

正負極引線，例如是從外裝構件25的內部朝向外部，以一個方向導出。正極引線22，是由例如鋁等導電性材料所形成，負極引線23，是由例如鎳、銅等導電性材料所形成。The positive and negative electrodes are led out in one direction from the inside of the exterior member 25 to the outside, for example. The positive electrode lead 22 is formed of a conductive material such as aluminum, and the negative electrode lead 23 is formed of a conductive material such as nickel and copper.

外裝構件25，例如是由融合層、金屬層、表面保護層依序積層而成之層合薄膜，此層合薄膜是以使融合層與電極體21相對向的方式，2片薄膜的融合層中的外周邊部彼此融合、或藉由黏合劑等來貼合。融合部，例如是聚乙烯或聚丙烯等的薄膜，金屬層是鋁箔等。保護層，例如是耐綸等。The exterior member 25 is, for example, a laminated film formed by sequentially laminating a fusion layer, a metal layer, and a surface protection layer. This laminated film is a fusion of two films in a manner that the fusion layer and the electrode body 21 face each other. The outer peripheral parts in the layer are fused with each other or bonded by an adhesive or the like. The fusion part is, for example, a film of polyethylene or polypropylene, and the metal layer is aluminum foil. The protective layer is, for example, nylon.

外裝構件25與正負極引線之間，***有密著薄膜24，以防止外部氣體侵入。此材料，例如是聚乙烯、聚丙烯、聚烯烴樹脂。An adhesive film 24 is inserted between the exterior member 25 and the positive and negative electrode leads to prevent the intrusion of external air. This material is, for example, polyethylene, polypropylene, and polyolefin resin.

[正極] 正極，例如與第1圖的負極10同樣地，在正極集電體的雙面或單面具有正極活性物質層。 [positive electrode] The positive electrode, for example, like the negative electrode 10 in FIG. 1, has a positive electrode active material layer on both sides or one side of a positive electrode current collector.

正極集電體，是由例如鋁等導電性材料所形成。The positive electrode current collector is formed of a conductive material such as aluminum.

正極活性物質層，包含能夠吸留、釋放鋰離子之正極材料中的任一種或二種以上，且可依據設計而包含黏著劑、導電助劑、分散劑等其他材料。此時，關於黏著劑、導電助劑的詳細資訊，與例如已記載的負極黏著劑、負極導電助劑相同。The positive electrode active material layer includes any one or two or more of positive electrode materials capable of occluding and releasing lithium ions, and may include other materials such as adhesives, conductive assistants, and dispersants according to the design. At this time, the detailed information about the adhesive and the conductive auxiliary agent is the same as, for example, the negative electrode adhesive and the negative conductive auxiliary agent described.

作爲正極材料，較理想是含鋰化合物。此含鋰化合物，可列舉例如：由鋰與過渡金屬元素所構成之複合氧化物、或具有鋰與過渡金屬元素之磷酸化合物。在這些正極材料中，較佳是具有鎳、鐵、錳、鈷的至少一種以上之化合物。作爲這些正極材料的化學式，是以例如Li xM1O 2或者Li yM2PO 4來表示。上述式中，M1、M2表示至少一種以上的過渡金屬元素。x、y的值隨著電池充放電狀態而表示不同的值，一般而言，是以0.05≦x≦1.10、0.05≦y≦1.10來表示。 As a positive electrode material, a lithium-containing compound is more desirable. Examples of the lithium-containing compound include a composite oxide composed of lithium and a transition metal element, or a phosphoric acid compound having lithium and a transition metal element. Among these positive electrode materials, it is preferable to have at least one compound of nickel, iron, manganese, and cobalt. The chemical formula of these positive electrode materials is represented by, for example, Li x M1O 2 or Li y M2PO 4 . In the above formula, M1 and M2 represent at least one transition metal element. The values of x and y show different values depending on the state of charge and discharge of the battery. Generally speaking, they are expressed as 0.05≦x≦1.10 and 0.05≦y≦1.10.

作爲具有鋰與過渡金屬元素之複合氧化物，可列舉例如：鋰鈷複合氧化物(Li xCoO 2)、鋰鎳複合氧化物(Li xNiO 2)等。作爲具有鋰與過渡金屬元素之磷酸化合物，可列舉例如：鋰鐵磷酸化合物(LiFePO 4)或鋰鐵錳磷酸化合物(LiFe 1-uMn uPO 4(0＜u＜1))等。原因在於，若使用這些正極材料，則能夠獲得高電池容量，並且亦能夠獲得優異的循環特性。 Examples of composite oxides having lithium and transition metal elements include lithium cobalt composite oxide (Li x CoO 2 ), lithium nickel composite oxide (Li x NiO 2 ), and the like. Examples of phosphate compounds having lithium and transition metal elements include lithium iron phosphate compounds (LiFePO 4 ), lithium iron manganese phosphate compounds (LiFe 1-u Mn u PO 4 (0<u<1)), and the like. The reason is that if these cathode materials are used, high battery capacity can be obtained, and excellent cycle characteristics can also be obtained.

[負極] 負極，具有與上述第1圖的鋰離子二次電池用負極10相同的構成，例如，在集電體11的雙面具有負極活性物質層12。此負極，較佳是：相對於從正極活性物質劑所獲得的電容量(作爲電池的充電容量)，負極充電容量變大。原因在於，能夠抑制負極上的鋰金屬析出。 [negative electrode] The negative electrode has the same structure as the negative electrode 10 for a lithium ion secondary battery in FIG. In this negative electrode, it is preferable that the negative electrode charge capacity is larger than the electric capacity obtained from the positive electrode active material agent (as the charge capacity of the battery). The reason is that the precipitation of lithium metal on the negative electrode can be suppressed.

正極活性物質層，設置於正極集電體的雙面的一部分上，且負極活性物質層亦設置於負極集電體的雙面的一部分上。此時，例如，設置於負極集電體上的負極活性物質層，設置有不存在相對向的正極活性物質層的區域。原因在於，要實行穩定的電池設計。The positive electrode active material layer is provided on a part of both sides of the positive electrode current collector, and the negative electrode active material layer is also provided on a part of the both sides of the negative electrode current collector. At this time, for example, the negative electrode active material layer provided on the negative electrode current collector is provided with a region where the opposite positive electrode active material layer does not exist. The reason is to implement a stable battery design.

在非相對向區域中，亦即在上述負極活性物質層與正極活性物質層不相對向的區域中，幾乎不會受到充放電的影響。因此，負極活性物質層的狀態在形成後能夠一直維持。藉此，能夠以不依賴於充放電的有無的方式，來再現性良好地且正確地調查負極活性物質的組成等。In the non-opposing region, that is, in the region where the above-mentioned negative electrode active material layer and the positive electrode active material layer are not facing each other, they are hardly affected by charge and discharge. Therefore, the state of the negative electrode active material layer can be maintained after being formed. Thereby, it is possible to accurately and reproducibly investigate the composition and the like of the negative electrode active material without depending on the presence or absence of charge and discharge.

[隔板] 隔板，將正極、負極隔離，來防止兩極接觸所引起的電流短路，並且使鋰離子通過。此隔板，是利用例如由合成樹脂或陶瓷所構成之多孔膜來形成，且可具有由2種以上的多孔膜積層而成之積層結構。作爲合成樹脂，可列舉例如：聚四氟乙烯、聚丙烯、聚乙烯等。 [Partition] The separator separates the positive electrode and the negative electrode to prevent a short circuit caused by the contact between the two electrodes, and allows lithium ions to pass. This separator is formed using a porous film made of, for example, synthetic resin or ceramics, and may have a laminated structure in which two or more types of porous films are laminated. Examples of synthetic resins include polytetrafluoroethylene, polypropylene, polyethylene, and the like.

[電解液] 在活性物質層的至少一部分、或隔板中，含浸有液狀的電解質(電解液)。此電解液，在溶劑中溶解有電解質鹽，且可包含添加劑等其他材料。 [Electrolyte] At least a part of the active material layer or the separator is impregnated with a liquid electrolyte (electrolyte). This electrolyte has electrolyte salts dissolved in a solvent, and may contain additives and other materials.

溶劑，可使用例如非水系溶劑。作爲非水系溶劑，可列舉例如：碳酸伸乙酯、碳酸伸丙酯、碳酸伸丁酯、碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯、碳酸甲丙酯、1,2-二甲氧基乙烷、或四氫呋喃等。其中，較理想是使用碳酸伸乙酯、碳酸伸丙酯、碳酸二甲酯、碳酸二乙酯、碳酸甲乙酯中的至少一種以上。原因在於，能夠獲得更良好的特性。又，此時，藉由組合碳酸伸乙酯、碳酸伸丙酯等高黏度溶劑、與碳酸二甲酯、碳酸甲乙酯、碳酸二乙酯等低黏度溶劑，能夠獲得更優勢的特性。原因在於，能夠提升電解質鹽的解離性和離子移動度。As the solvent, for example, a non-aqueous solvent can be used. Examples of non-aqueous solvents include ethylene carbonate, propylene carbonate, butyl carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, and 1,2-dimethyl carbonate. Oxyethane, or tetrahydrofuran, etc. Among them, it is preferable to use at least one of ethylene carbonate, propylene carbonate, dimethyl carbonate, diethyl carbonate, and ethyl methyl carbonate. The reason is that better characteristics can be obtained. In addition, at this time, by combining high-viscosity solvents such as ethylene carbonate and propylene carbonate with low-viscosity solvents such as dimethyl carbonate, ethyl methyl carbonate, and diethyl carbonate, more advantageous characteristics can be obtained. The reason is that the dissociation property and ion mobility of the electrolyte salt can be improved.

當使用合金系負極時，尤其，作為溶劑，較理想是含有鹵化鏈狀碳酸酯或鹵化環狀碳酸酯中的至少一種。藉此，尤其在充電時，能夠在負極活性物質表面形成穩定的被膜。此處，鹵化鏈狀碳酸酯，是指具有鹵素作為構成元素(至少一個氫被鹵素取代)之鏈狀碳酸酯。又，鹵化環狀碳酸酯，是指具有鹵素作為構成元素(亦即至少一個氫被鹵素取代)之環狀碳酸酯。When an alloy-based negative electrode is used, in particular, as a solvent, it is preferable to contain at least one of a halogenated chain carbonate or a halogenated cyclic carbonate. Thereby, it is possible to form a stable coating film on the surface of the negative electrode active material especially during charging. Here, the halogenated chain carbonate refers to a chain carbonate having halogen as a constituent element (at least one hydrogen is substituted by halogen). In addition, the halogenated cyclic carbonate refers to a cyclic carbonate having a halogen as a constituent element (that is, at least one hydrogen is substituted by a halogen).

鹵素的種類，並無特別限定，較佳是氟。原因在於，相較於其他鹵素，能夠形成更優質的被膜。又，鹵素數量愈多愈理想。原因在於，所獲得的被膜更穩定，且能夠減少電解液的分解反應。The type of halogen is not particularly limited, but fluorine is preferred. The reason is that compared with other halogens, it is possible to form a higher quality film. In addition, the more halogens, the more ideal it is. The reason is that the obtained film is more stable and the decomposition reaction of the electrolyte can be reduced.

鹵化鏈狀碳酸酯，可列舉例如：碳酸氟甲基甲酯、碳酸二氟甲基甲酯等。作為鹵化環狀碳酸酯，可列舉例如：4-氟-1,3-二氧五環-2-酮、4,5-1,3-二氧五環-2-酮等。Examples of halogenated chain carbonates include fluoromethyl methyl carbonate and difluoromethyl methyl carbonate. Examples of halogenated cyclic carbonates include 4-fluoro-1,3-dioxolane-2-one, 4,5-1,3-dioxolane-2-one, and the like.

較佳是：作爲溶劑添加物，包含不飽和碳鍵環狀碳酸酯。原因在於，在充放電時能夠於負極表面形成穩定的被膜，而能夠抑制電解液的分解反應。作爲不飽和碳鍵環狀碳酸酯，可列舉例如：碳酸伸乙烯酯(vinylene carbonate)或碳酸乙烯基伸乙酯等。Preferably, as a solvent additive, an unsaturated carbon bond cyclic carbonate is contained. The reason is that a stable coating can be formed on the surface of the negative electrode during charge and discharge, and the decomposition reaction of the electrolyte can be suppressed. Examples of unsaturated carbon bond cyclic carbonates include vinylene carbonate and vinyl ethylene carbonate.

又，較佳是：作爲溶劑添加物，包含磺內酯(環狀磺酸酯)。原因在於，能夠提升電池的化學穩定性。作爲磺內酯，可列舉例如：丙烷磺內酯、丙烯磺內酯。Furthermore, it is preferable to contain sultone (cyclic sulfonate) as a solvent additive. The reason is that the chemical stability of the battery can be improved. Examples of sultones include propane sultone and propene sultone.

進一步，溶劑較佳是包含酸酐。原因在於，能夠提升電解液的化學穩定性。作爲酸酐，可列舉例如，丙烷二磺酸酐。Further, the solvent preferably contains acid anhydride. The reason is that the chemical stability of the electrolyte can be improved. As an acid anhydride, propane disulfonic anhydride is mentioned, for example.

電解質鹽，可包含例如鋰鹽等輕金屬鹽中的任一種以上。作爲鋰鹽，可列舉例如：六氟磷酸鋰(LiPF 6)、四氟硼酸鋰(LiBF 4)等。 The electrolyte salt may include any one or more of light metal salts such as lithium salt. Examples of the lithium salt include lithium hexafluorophosphate (LiPF 6 ), lithium tetrafluoroborate (LiBF 4 ), and the like.

電解質鹽的含量，較佳是：相對於溶劑，為0.5 mol/kg以上且2.5 mol/kg以下。原因在於，能夠獲得高離子傳導性。The content of the electrolyte salt is preferably 0.5 mol/kg or more and 2.5 mol/kg or less relative to the solvent. The reason is that high ion conductivity can be obtained.

[層合薄膜型二次電池的製造方法] 在本發明中，能夠使用藉由上述本發明的負極活性物質的製造方法所製造出來的負極活性物質來製作負極，並且能夠使用該製作出來的負極來製造鋰離子二次電池。 [Manufacturing Method of Laminated Film Type Secondary Battery] In the present invention, the negative electrode active material produced by the method for producing the negative electrode active material of the present invention can be used to produce a negative electrode, and the produced negative electrode can be used to produce a lithium ion secondary battery.

一開始先使用上述正極材料來製作正極電極。首先，將正極活性物質，根據需要而與黏著劑、導電助劑等混合，來作成正極混合劑後，分散於有機溶劑中，來作成正極混合劑漿料。繼而，利用具有刀輥或模頭之模具式塗佈機(die coater)等塗佈裝置，來將混合劑漿料塗佈在正極集電體上，並進行熱風乾燥，來獲得正極活性物質層。最後，利用輥壓機等來壓縮成型正極活性物質層。此時，可進行加熱，並且可重複複數次加熱或壓縮。In the beginning, the positive electrode material described above was used to make the positive electrode. First, the positive electrode active material is mixed with a binder, a conductive auxiliary agent, etc. as needed to form a positive electrode mixture, and then dispersed in an organic solvent to form a positive electrode mixture slurry. Then, a coating device such as a die coater with a knife roll or a die is used to coat the mixture slurry on the positive electrode current collector and dry it with hot air to obtain a positive electrode active material layer . Finally, the positive electrode active material layer is compression-molded using a roll press or the like. At this time, heating can be performed, and heating or compression can be repeated multiple times.

繼而，使用與製作上述鋰離子二次電池用負極10時相同的作業程序，在負極集電體上形成負極活性物質層，來製作負極。Then, using the same operating procedure as when producing the aforementioned negative electrode 10 for a lithium ion secondary battery, a negative electrode active material layer was formed on the negative electrode current collector to produce a negative electrode.

在製作正極和負極時，於正極和負極集電體的雙面上形成各活性物質層。此時，在任一電極中，雙面部的活性物質塗佈長度可以不一致(參照第1圖)。When producing the positive electrode and the negative electrode, each active material layer is formed on both sides of the positive electrode and the negative electrode current collector. At this time, in any electrode, the active material coating length of the double-sided portion may not be uniform (refer to Fig. 1).

繼而，製備電解液。繼而，利用超音波焊接等，向正極集電體安裝正極引線22，並且向負極集電體安裝負極引線23。繼而，隔著隔板，積層或捲繞正極與負極，來製作捲繞電極體21，並在其最外周部黏合保護膠帶。繼而，以成爲扁平形狀的方式來成型捲繞體。繼而，將捲繞電極體夾入已折叠的薄膜狀外裝構件25之間，之後利用熱融合法黏合外裝構件的絕緣部彼此，僅將一個方向設爲開放狀態，來將捲繞電極體封入。在正極引線和負極引線與外裝構件之間***密著薄膜。從開放部投入特定量的上述製備的電解液，並實行真空含浸。含浸後，利用真空熱融合法使開放部黏結。以上述方式進行，能夠製造層合薄膜型二次電池20。 [實施例] Then, an electrolyte is prepared. Then, by ultrasonic welding or the like, the positive electrode lead 22 is attached to the positive electrode current collector, and the negative electrode lead 23 is attached to the negative electrode current collector. Then, the positive electrode and the negative electrode are laminated or wound with a separator interposed therebetween to produce a wound electrode body 21, and a protective tape is adhered to the outermost periphery of the wound electrode body 21. Then, the wound body is formed into a flat shape. Then, the wound electrode body is sandwiched between the folded film-like outer covering members 25, and then the insulating parts of the outer covering member are bonded together by the thermal fusion method, and only one direction is set to an open state, so that the wound electrode body Enclosed. An adhesive film is inserted between the positive electrode lead and the negative electrode lead and the exterior member. A specific amount of the above-prepared electrolyte solution was injected from the open part, and vacuum impregnation was performed. After impregnation, vacuum thermal fusion is used to bond the open part. By proceeding in the above manner, the laminated thin film type secondary battery 20 can be manufactured. [Example]

以下，示出本發明的實施例和比較例來更具體地說明本發明，但是本發明並不受限於這些實施例。Hereinafter, examples and comparative examples of the present invention are shown to explain the present invention more specifically, but the present invention is not limited to these examples.

(實施例1-1) 根據以下程序，來製作第4圖所示之層合薄膜型鋰離子二次電池20。 (Example 1-1) According to the following procedure, the laminated thin film type lithium ion secondary battery 20 shown in FIG. 4 was produced.

一開始先製作正極。正極活性物質，是混合95質量%的鋰鎳鈷複合氧化物也就是LiNi 0.7Co 0.25Al 0.05O、2.5質量%的正極導電助劑、及2.5質量%的正極黏著劑(聚偏氟乙烯，PVDF)，來作成正極混合劑。繼而，使正極混合劑分散於有機溶劑(N-甲基-2-吡咯啶酮，NMP)中，來作成糊狀的漿料。繼而，利用具有模頭之塗佈裝置，將漿料塗佈在正極集電體的雙面，並利用熱風式乾燥裝置進行乾燥。此時，正極集電體是使用厚度15μm的正極集電體。最後利用輥壓來實行壓縮成型。 At the beginning, the positive electrode is made. The positive electrode active material is mixed with 95% by mass of lithium nickel cobalt composite oxide, which is LiNi 0.7 Co 0.25 Al 0.05 O, 2.5% by mass of positive electrode conductive aid, and 2.5% by mass of positive electrode adhesive (polyvinylidene fluoride, PVDF) ), to make a positive electrode mixture. Then, the positive electrode mixture was dispersed in an organic solvent (N-methyl-2-pyrrolidone, NMP) to form a paste-like slurry. Then, the slurry was coated on both sides of the positive electrode current collector using a coating device with a die, and dried using a hot air drying device. At this time, a positive electrode current collector with a thickness of 15 μm was used as the positive electrode current collector. Finally, roll compression is used to perform compression molding.

繼而，製作負極。首先，以下述方式來製作負極活性物質。將由金屬矽與二氧化矽混合而得之原料，導入反應爐中，在10Pa的真空度的環境中進行汽化，然後沉積於吸附板上，並充分冷却後，取出沉積物，並利用球磨機進行粉碎。以這樣的方式來獲得之矽化合物粒子的SiO x的x值是0.5。繼而，藉由分級來調整矽化合物粒子的粒徑。之後，藉由實行熱裂解CVD，來在矽化合物粒子的表面上被覆碳材料。 Then, a negative electrode was fabricated. First, the negative electrode active material was produced in the following manner. The raw material obtained by mixing metallic silicon and silicon dioxide is introduced into the reaction furnace, vaporized in a 10Pa vacuum environment, and then deposited on the adsorption plate, and after sufficient cooling, the deposit is taken out and crushed by a ball mill . The x value of SiO x of the silicon compound particles obtained in this way is 0.5. Then, the particle size of the silicon compound particles is adjusted by classification. Afterwards, by performing thermal cracking CVD, the surface of the silicon compound particles is coated with a carbon material.

繼而，根據氧化還原法，對於被覆有碳被膜之矽化合物粒子(負極活性物質粒子)***鋰，來實行改質。首先，將負極活性物質粒子與鋰片浸泡在溶液(溶液C)中，該溶液是將芳香族化合物也就是萘溶於四氫呋喃(以下稱為THF)而得。此時，此溶液C，是藉由下述方式製作：依0.2mol/L的濃度來將萘溶於THF溶劑中後，相對於此THF與萘之混合液，添加10質量%的質量分率的鋰片。又，浸泡負極活性物質粒子時，溶液的溫度是20℃，浸泡時間設為20小時。之後，過濾取得負極活性物質粒子。藉由以上處理，來對負極活性物質粒子***鋰。Then, according to the oxidation-reduction method, lithium is inserted into the silicon compound particles (negative electrode active material particles) covered with the carbon film to perform modification. First, the negative electrode active material particles and the lithium sheet are immersed in a solution (solution C), which is obtained by dissolving an aromatic compound, namely naphthalene, in tetrahydrofuran (hereinafter referred to as THF). At this time, this solution C is prepared by the following method: After dissolving naphthalene in a THF solvent at a concentration of 0.2 mol/L, add 10% by mass to the mixed solution of THF and naphthalene. Of lithium tablets. In addition, when immersing the negative electrode active material particles, the temperature of the solution was 20°C, and the immersion time was set to 20 hours. After that, the negative electrode active material particles were obtained by filtration. Through the above process, lithium is inserted into the negative electrode active material particles.

繼而，在氬氣氛下，以600℃對所獲得的矽化合物粒子實行熱處理24小時，來實行鋰化合物的穩定化。Then, in an argon atmosphere, the obtained silicon compound particles were heat-treated at 600° C. for 24 hours to stabilize the lithium compound.

繼而，將分散有羧甲基纖維素的銨鹽(CMC-NH 4)與磷酸鋁(AlPO 4)之乙醇，噴霧在負極活性物質粒子上，並使負極活性物質粒子乾燥。負極活性物質粒子的CMC-NH 4的含量是1質量%，AlPO 4的含量是2質量%。 Then, ethanol in which the ammonium salt of carboxymethyl cellulose (CMC-NH 4 ) and aluminum phosphate (AlPO 4 ) are dispersed is sprayed on the negative electrode active material particles, and the negative electrode active material particles are dried. The content of CMC-NH 4 in the negative electrode active material particles is 1% by mass, and the content of AlPO 4 is 2% by mass.

繼而，將製作負極用的負極活性物質粒子(矽系負極活性物質)與碳系活性物質，依2：8的質量比進行摻合，來製作負極活性物質。此處，作為碳系活性物質，是使用下述碳系活性物質：將由瀝青層被覆之天然石墨和人造石墨，依5：5的質量比混合而得。又，碳系活性物質的中值粒徑為20μm。Then, the negative electrode active material particles (silicon-based negative electrode active material) for making the negative electrode and the carbon-based active material were blended in a mass ratio of 2:8 to prepare the negative electrode active material. Here, as the carbon-based active material, the following carbon-based active material is used: a mixture of natural graphite and artificial graphite coated with a pitch layer in a mass ratio of 5:5. In addition, the median particle diameter of the carbon-based active material is 20 μm.

繼而，將所製作的負極活性物質、導電助劑1(碳奈米管，CNT)、導電助劑2(中值粒徑為約50μm之碳微粒子)、苯乙烯丁二烯橡膠(苯乙烯丁二烯共聚物，以下稱為SBR)、羧甲基纖維素(以下稱為CMC)，依92.5：1：1：2.5：3的乾燥質量比進行混合後，以純水稀釋，來作成負極混合劑漿料。再者，上述SBR、CMC是負極黏結劑(負極黏著劑)。Then, the produced negative electrode active material, conductive assistant 1 (carbon nanotube, CNT), conductive assistant 2 (carbon fine particles with a median diameter of about 50 μm), styrene butadiene rubber (styrene butadiene Diene copolymer, hereinafter referred to as SBR), carboxymethyl cellulose (hereinafter referred to as CMC), after mixing in a dry mass ratio of 92.5:1:1:2.5:3, diluted with pure water to make a negative electrode mixture Agent slurry. Furthermore, the above-mentioned SBR and CMC are negative electrode binders (negative electrode binders).

此處，為了評估包含負極活性物質粒子之水系漿料的穩定性，將所製作的負極混合劑漿料的一部分，除了用於製作二次電池以外，另外取出30g，保存在20℃，並測定自製作負極混合劑漿料後起算至產生氣體為止的時間。Here, in order to evaluate the stability of the aqueous slurry containing the negative electrode active material particles, a part of the prepared negative electrode mixture slurry was taken out, except for the production of secondary batteries, and another 30g was taken out, stored at 20°C, and measured The time from when the negative electrode mixture slurry is produced until gas is generated.

又，作爲負極集電體，使用厚度15μm的電解銅箔。此電解銅箔中，包含各70質量ppm的濃度的碳和硫。最後，將負極混合劑漿料塗佈在負極集電體上，並在真空環境中實行100℃×1小時的乾燥。乾燥後，負極的單面上的每單位面積的負極活性物質層的沉積量(亦稱為面積密度)，是5mg/cm 2。 In addition, as the negative electrode current collector, an electrolytic copper foil having a thickness of 15 μm was used. This electrolytic copper foil contains carbon and sulfur at a concentration of 70 mass ppm each. Finally, the negative electrode mixture slurry was coated on the negative electrode current collector and dried at 100° C. for 1 hour in a vacuum environment. After drying, the deposition amount (also referred to as area density) of the negative electrode active material layer per unit area on one side of the negative electrode was 5 mg/cm 2 .

繼而，將溶劑(4-氟-1,3-二氧五環-2-酮(FEC)、碳酸伸乙酯(EC)及碳酸二甲酯(DMC))混合後，溶解電解質鹽(六氟磷酸鋰，LiPF 6)，來製備電解液。此時，將溶劑的組成依體積比設爲FEC：EC：DEC＝10：20：70，且將電解質鹽的含量設爲相對於溶劑是1.2mol/kg。 Then, after mixing the solvents (4-fluoro-1,3-dioxolane-2-one (FEC), ethylene carbonate (EC), and dimethyl carbonate (DMC)), the electrolyte salt (lithium hexafluorophosphate, LiPF 6 ) to prepare the electrolyte. At this time, the composition of the solvent was set to FEC:EC:DEC=10:20:70 by volume ratio, and the content of the electrolyte salt was set to 1.2 mol/kg with respect to the solvent.

繼而，以下述方式進行來組裝二次電池。一開始先向正極集電體的一端超音波焊接鋁引線，且向負極集電體焊接鎳引線。繼而，依序積層正極、隔板、負極、隔板，然後縱向捲繞，來獲得捲繞電極體。以PET保護膠帶固定其捲繞結束部分。隔板，是使用積層薄膜(12μm)，該積層薄膜是由以多孔性聚丙烯爲主要成分之薄膜，夾於以多孔性聚乙烯爲主要成分的薄膜中而成。繼而，將電極體夾於外裝構件間後，除了一邊外，將外周邊部彼此熱融合，並收納電極體於內部。外裝構件，是使用由耐綸薄膜、鋁箔、及聚丙烯薄膜積層而成之鋁層合薄膜。繼而，從開口部注入製備的電解液，並在真空環境下含浸，之後進行熱融合來密封。Then, the secondary battery was assembled in the following manner. In the beginning, an aluminum lead was ultrasonically welded to one end of the positive electrode current collector, and a nickel lead was welded to the negative electrode current collector. Then, the positive electrode, the separator, the negative electrode, and the separator are sequentially layered, and then longitudinally wound to obtain a wound electrode body. Fix the winding end part with PET protective tape. The separator uses a laminated film (12μm), which is made of a film with porous polypropylene as the main component sandwiched between a film with porous polyethylene as the main component. Then, after sandwiching the electrode body between the exterior members, except for one side, the outer peripheral parts are thermally fused with each other, and the electrode body is accommodated inside. The exterior component is an aluminum laminate film made of nylon film, aluminum foil, and polypropylene film. Then, the prepared electrolyte is injected from the opening, impregnated in a vacuum environment, and then thermally fused to seal.

評估以上述方式進行而製作之二次電池的循環特性和初次充放電特性。The cycle characteristics and initial charge-discharge characteristics of the secondary battery produced in the above manner were evaluated.

關於循環特性，以下述方式進行調查。一開始，為了電池穩定化，先在25℃的環境下，以0.2C實行2次循環充放電，並測定第2次循環的放電容量。繼而，實行充放電至總循環數成為499次循環為止，並測定每次放電容量。最後，將以0.2C充放電來獲得之第500次循環的放電容量除以第2次循環的放電容量，來計算出容量維持率(以下亦僅稱為維持率)。一般循環，亦即從第3次循環至第499次循環為止，是以充電0.7C、放電0.5C來實行充放電。Regarding the cycle characteristics, the investigation was carried out in the following manner. In the beginning, in order to stabilize the battery, the charge and discharge were performed 2 cycles at 0.2C in an environment of 25°C, and the discharge capacity of the second cycle was measured. Then, charge and discharge were performed until the total number of cycles reached 499 cycles, and the discharge capacity per discharge was measured. Finally, the discharge capacity of the 500th cycle obtained by charging and discharging at 0.2C is divided by the discharge capacity of the second cycle to calculate the capacity retention rate (hereinafter also simply referred to as retention rate). In the general cycle, that is, from the 3rd cycle to the 499th cycle, charging and discharging are performed by charging at 0.7C and discharging at 0.5C.

當調查初次充放電特性時，計算出初次效率(以下亦有時稱為起始效率)。初次效率，是由以下述式來表示的公式計算出來：初次效率(%)＝(初次放電容量／初次充電容量)×100。環境溫度，設為與調查循環特性時相同。When investigating the initial charge and discharge characteristics, the initial efficiency (hereinafter also sometimes referred to as the initial efficiency) is calculated. The initial efficiency is calculated by the formula represented by the following formula: initial efficiency (%)=(initial discharge capacity/initial charge capacity)×100. The ambient temperature is set to be the same as when investigating the cycle characteristics.

(實施例1-2～實施例1-3、比較例1-1、1-2) 除了調整矽化合物的塊體內氧量以外，與實施例1-1同樣地實行二次電池的製造。此時，藉由改變矽化合物在原料中的金屬矽與二氧化矽的比例和加熱溫度，來調整氧量。將實施例1-1～1-3、比較例1-1、1-2中的以SiO x來表示的矽化合物的x值表示於表1中。 (Example 1-2 to Example 1-3, Comparative Examples 1-1, 1-2) The production of a secondary battery was carried out in the same manner as in Example 1-1 except that the amount of oxygen in the silicon compound was adjusted. At this time, the amount of oxygen is adjusted by changing the ratio of metallic silicon to silicon dioxide in the silicon compound in the raw material and the heating temperature. Table 1 shows the x value of the silicon compound represented by SiO x in Examples 1-1 to 1-3 and Comparative Examples 1-1 and 1-2.

此時，實施例1-1～1-3及比較例1-1、1-2的矽系活性物質粒子，具有如下所述的性質。負極活性物質粒子中的矽系活性物質粒子的中值粒徑為8μm。矽化合物粒子的內部中，包含Li 2Si 2O 5和Li 2SiO 3。又，矽化合物的根據X射線繞射所獲得的由Si(111)結晶面所導致的繞射峰的半值寬(2θ)為2.257°，由該Si(111)結晶面所導致的微晶尺寸為3.77nm。又，被覆於表面的碳材料的平均厚度為50nm。 At this time, the silicon-based active material particles of Examples 1-1 to 1-3 and Comparative Examples 1-1 and 1-2 had the following properties. The median diameter of the silicon-based active material particles in the negative electrode active material particles was 8 μm. The inside of the silicon compound particle contains Li 2 Si 2 O 5 and Li 2 SiO 3 . In addition, the half-value width (2θ) of the diffraction peak due to the Si(111) crystal plane obtained by X-ray diffraction of the silicon compound is 2.257°, and the crystallites due to the Si(111) crystal plane The size is 3.77nm. In addition, the average thickness of the carbon material covering the surface was 50 nm.

又，在上述所有實施例和比較例中，都顯現了由 29Si-MAS-NMR波譜所獲得的在作為化學位移值的－60～－95ppm處所呈現的矽與矽酸鋰區域的峰。又，在上述所有實施例和比較例中，由 29Si-MAS-NMR波譜所獲得的在作為化學位移值的－60～－95ppm處所呈現的矽與矽酸鋰區域的最大峰強度值A與在－96～－150ppm處所呈現的SiO 2區域的峰強度值B的關係為A＞B。 In addition, in all the above-mentioned Examples and Comparative Examples, peaks in the region of silicon and lithium silicate appearing at -60 to -95 ppm, which are chemical shift values, obtained from 29 Si-MAS-NMR spectroscopy are shown. In addition, in all the above examples and comparative examples, the maximum peak intensity value A of silicon and lithium silicate in the region of -60 to -95 ppm, which is the chemical shift value, obtained from 29 Si-MAS-NMR spectroscopy and The relationship between the peak intensity value B of the SiO 2 region appearing at -96 to -150 ppm is A>B.

將實施例1-1～1-3及比較例1-1、1-2的評估結果表示於表1中。Table 1 shows the evaluation results of Examples 1-1 to 1-3 and Comparative Examples 1-1 and 1-2.

[表1] SiOx：D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； CMC-NH 4含量：1質量%；AlPO 4含量：2質量%；濕式混合法 表1 x 容量維持率 (%) 起始效率 (%) 至產生氣體為止的時間 比較例1-1 0.3 49 89.3 1天 實施例1-1 0.5 65 88.1 2天 實施例1-2 1 68 87.3 3天 實施例1-3 1.6 70 87.2 3天 比較例1-2 1.8 － － － [Table 1] SiOx: D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; carbon material: Average thickness 50nm, half-value width 2.257°; crystallite 3.77nm; modification method: redox method; A>B; CMC-NH 4 content: 1% by mass; AlPO 4 content: 2% by mass; wet mixing method Table 1 x Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Comparative example 1-1 0.3 49 89.3 1 day Example 1-1 0.5 65 88.1 2 days Example 1-2 1 68 87.3 3 days Example 1-3 1.6 70 87.2 3 days Comparative example 1-2 1.8 - - -

如表1所示，在以SiOx來表示的矽化合物中，當x值在0.5≦x≦1.6的範圍外時，電池特性惡化。例如，如比較例1.1所示，當氧不足時(x＝0.3)，雖然初次效率提升，但是容量維持率顯著惡化。另一方面，如比較例1-2所示，當氧量較多時(x＝1.8)，發生導電性下降的情形，且實質上無法顯現矽氧化物的容量，因此停止評估。又，在實施例1-1～1-3中，至產生氣體為止的時間為2天以上，可知水系負極漿料穩定性較高。再者，在比較例1-2中，未實行至產生氣體為止的時間的測定。As shown in Table 1, in the silicon compound represented by SiOx, when the value of x is outside the range of 0.5≦x≦1.6, battery characteristics deteriorate. For example, as shown in Comparative Example 1.1, when oxygen is insufficient (x=0.3), although the initial efficiency is improved, the capacity maintenance rate significantly deteriorates. On the other hand, as shown in Comparative Example 1-2, when the amount of oxygen is large (x=1.8), the conductivity decreases, and the capacity of silicon oxide cannot be substantially expressed, so the evaluation was stopped. In addition, in Examples 1-1 to 1-3, the time until the gas was generated was 2 days or more, and it was found that the stability of the aqueous negative electrode slurry was high. In addition, in Comparative Example 1-2, the measurement of the time until gas generation was not performed.

(實施例2-1～實施例2-2) 將矽化合物粒子的內部包含的矽酸鋰的種類變更成如表2所示，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Example 2-1 to Example 2-2) The type of lithium silicate contained in the silicon compound particles was changed as shown in Table 2. In addition, a secondary battery was produced under the same conditions as in Example 1-2, and the cycle characteristics, primary efficiency, and water-based negative electrode slurry were evaluated. The stability.

(比較例2-1) 不對矽化合物粒子***鋰，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Comparative Example 2-1) Without inserting lithium into the silicon compound particles, a secondary battery was fabricated under the same conditions as in Example 1-2, and the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry were evaluated.

將實施例2-1～實施例2-2、比較例2-1的結果表示於表2中。Table 2 shows the results of Examples 2-1 to 2-2 and Comparative Example 2-1.

[表2] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； CMC-NH 4含量：1質量%；AlPO 4含量：2質量%；濕式混合法 表2 矽酸鋰 容量維持率 (%) 起始效率 (%) 至產生氣體為止的時間 實施例2-1 Li 2Si 2O 5 69 87.5 4天 實施例2-2 Li 4SiO 4、Li 2SiO 3 73 87.1 1天 實施例1-2 Li 2Si 2O 5、Li 2SiO 3 70 87.3 3天 比較例2-1 － 72 78.2 無 [Table 2] SiOx: x = 1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20 mass%; carbon material: average thickness 50 nm, half-value width 2.257° ; Microcrystal 3.77nm; Modification method: Redox method; A>B; CMC-NH 4 content: 1% by mass; AlPO 4 content: 2% by mass; wet mixing method Table 2 Lithium Silicate Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 2-1 Li 2 Si 2 O 5 69 87.5 4 days Example 2-2 Li 4 SiO 4 , Li 2 SiO 3 73 87.1 1 day Example 1-2 Li 2 Si 2 O 5 , Li 2 SiO 3 70 87.3 3 days Comparative example 2-1 - 72 78.2 without

藉由矽化合物粒子包含像Li 2SiO 3、Li 4SiO 4這樣穩定的矽酸鋰，容量維持率、起始效率以良好平衡的方式提升。尤其，當包含2種矽酸鋰時，容量維持率、起始效率以更良好平衡的方式提升。又，在實施例1-2、2-1、2-2中，至產生氣體為止的時間為1天以上，而獲得充分的水性負極漿料的穩定性。另一方面，如比較例2-1所示，當矽化合物粒子未含有鋰化合物時，雖然沒有產生氣體，但起始效率顯著下降。 Since the silicon compound particles contain stable lithium silicate like Li 2 SiO 3 and Li 4 SiO 4 , the capacity maintenance rate and initial efficiency are improved in a well-balanced manner. In particular, when two types of lithium silicate are included, the capacity maintenance rate and initial efficiency are improved in a more well-balanced manner. In addition, in Examples 1-2, 2-1, and 2-2, the time until the gas was generated was 1 day or more, and sufficient stability of the aqueous negative electrode slurry was obtained. On the other hand, as shown in Comparative Example 2-1, when the silicon compound particles do not contain a lithium compound, although no gas is generated, the initial efficiency is significantly reduced.

(實施例3-1～實施例3-38) 將羧甲基纖維素(CMC)的鹽的含量、金屬鹽的種類、及金屬鹽的含量變更成如表3所示，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Example 3-1 to Example 3-38) The content of the carboxymethyl cellulose (CMC) salt, the type of metal salt, and the content of the metal salt were changed as shown in Table 3. In addition, the secondary battery was produced under the same conditions as in Example 1-2, and Evaluate cycle characteristics, initial efficiency, and stability of aqueous anode slurry.

將實施例3-1～實施例3-38的結果表示於表3中。The results of Example 3-1 to Example 3-38 are shown in Table 3.

[表3] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； 濕式混合法 表3 CMC的鹽的種類 CMC的鹽的含量 (質量%) 金屬鹽 的種類 金屬鹽 的含量 (質量%) 容量 維持率 (%) 起始 效率 (%) 至產生氣體為止的時間 實施例3-1 CMC-NH 4 1 Mg(NO 3) 2 2 71 87.1 2天 實施例3-2 CMC-NH 4 1 Mg 3(PO 4) 2 2 70 87.3 3天 實施例3-3 CMC-NH 4 1 AlCl 3 2 68 87 2天 實施例3-4 CMC-NH 4 1 Al(NO 3) 3 2 70 87.1 3天 實施例1-2 CMC-NH 4 1 AlPO 4 2 70 87.3 3天 實施例3-5 CMC-NH 4 1 Mg(NO 3) 2 1 71 87 1天 實施例3-6 CMC-NH 4 1 Mg 3(PO 4) 2 1 70 87.3 2天 實施例3-7 CMC-NH 4 1 AlCl 3 1 69 87 1天 實施例3-8 CMC-NH 4 1 Al(NO 3) 3 1 71 87.1 2天 實施例3-9 CMC-NH 4 1 AlPO 4 1 69 87.2 2天 實施例3-10 CMC-NH 4 1 Mg(NO 3) 2 0.5 71 87.1 13小時 實施例3-11 CMC-NH 4 1 Mg 3(PO 4) 2 0.5 69 87.3 22小時 實施例3-12 CMC-NH 4 1 AlCl 3 0.5 68 87.2 14小時 實施例3-13 CMC-NH 4 1 Al(NO 3) 3 0.5 69 87.1 21小時 實施例3-14 CMC-NH 4 1 AlPO 4 0.5 70 87 21小時 實施例3-15 CMC-NH 4 0.1 Mg(NO 3) 2 2 69 87.3 1天 實施例3-16 CMC-NH 4 0.1 Mg 3(PO 4) 2 2 68 87.3 1天 實施例3-17 CMC-NH 4 0.1 AlCl 3 2 67 87.2 1天 實施例3-18 CMC-NH 4 0.1 AlPO 4 2 69 87.1 1天 實施例3-19 CMC-NH 4 0.5 Mg(NO 3) 2 2 71 87 2天 實施例3-20 CMC-NH 4 0.5 Mg 3(PO 4) 2 2 70 87.2 2天 實施例3-21 CMC-NH 4 0.5 AlCl 3 2 68 87.2 2天 實施例3-22 CMC-NH 4 0.5 AlPO 4 2 69 87.1 2天 實施例3-23 CMC-NH 4 2 Mg(NO 3) 2 3 69 87.3 2天 實施例3-24 CMC-NH 4 2 Mg 3(PO 4) 2 3 68 87.1 2天 實施例3-25 CMC-NH 4 2 AlCl 3 3 68 87.2 2天 實施例3-26 CMC-NH 4 2 AlPO 4 3 69 87.3 3天 實施例3-27 CMC-NH 4 5 Mg(NO 3) 2 5 70 87.2 2天 實施例3-28 CMC-NH 4 5 Mg 3(PO 4) 2 5 71 87.1 3天 實施例3-29 CMC-NH 4 5 AlCl 3 5 71 87 2天 實施例3-30 CMC-NH 4 5 AlPO 4 5 70 87.1 3天 實施例3-31 CMC-NH 4 0.1 Mg(NO 3) 2 0.1 68 87.1 15小時 實施例3-32 CMC-NH 4 0.1 Mg 3(PO 4) 2 0.1 69 87 16小時 實施例3-33 CMC-NH 4 0.1 AlCl 3 0.1 71 87.2 16小時 實施例3-34 CMC-NH 4 0.1 AlPO 4 0.1 70 87.3 15小時 實施例3-35 CMC-NH 4 0.1 Mg(NO 3) 2 0.5 70 87.2 1天 實施例3-36 CMC-NH 4 0.1 Mg 3(PO 4) 2 0.5 70 87.1 21小時 實施例3-37 CMC-NH 4 0.1 AlCl 3 0.5 70 87.1 1天 實施例3-38 CMC-NH 4 0.1 AlPO 4 0.5 71 87 1天 [Table 3] SiOx: x=1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; Carbon material: average thickness 50nm half-value width 2.257°; crystallite 3.77nm; modification method: redox method; A>B; wet mixing method table 3 Types of CMC salt CMC salt content (mass%) Types of metal salts Metal salt content (mass%) Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 3-1 CMC-NH 4 1 Mg(NO 3 ) 2 2 71 87.1 2 days Example 3-2 CMC-NH 4 1 Mg 3 (PO 4 ) 2 2 70 87.3 3 days Example 3-3 CMC-NH 4 1 AlCl 3 2 68 87 2 days Example 3-4 CMC-NH 4 1 Al(NO 3 ) 3 2 70 87.1 3 days Example 1-2 CMC-NH 4 1 AlPO 4 2 70 87.3 3 days Example 3-5 CMC-NH 4 1 Mg(NO 3 ) 2 1 71 87 1 day Example 3-6 CMC-NH 4 1 Mg 3 (PO 4 ) 2 1 70 87.3 2 days Example 3-7 CMC-NH 4 1 AlCl 3 1 69 87 1 day Example 3-8 CMC-NH 4 1 Al(NO 3 ) 3 1 71 87.1 2 days Example 3-9 CMC-NH 4 1 AlPO 4 1 69 87.2 2 days Example 3-10 CMC-NH 4 1 Mg(NO 3 ) 2 0.5 71 87.1 13 hours Example 3-11 CMC-NH 4 1 Mg 3 (PO 4 ) 2 0.5 69 87.3 22 hours Example 3-12 CMC-NH 4 1 AlCl 3 0.5 68 87.2 14 hours Example 3-13 CMC-NH 4 1 Al(NO 3 ) 3 0.5 69 87.1 21 hours Example 3-14 CMC-NH 4 1 AlPO 4 0.5 70 87 21 hours Example 3-15 CMC-NH 4 0.1 Mg(NO 3 ) 2 2 69 87.3 1 day Example 3-16 CMC-NH 4 0.1 Mg 3 (PO 4 ) 2 2 68 87.3 1 day Example 3-17 CMC-NH 4 0.1 AlCl 3 2 67 87.2 1 day Example 3-18 CMC-NH 4 0.1 AlPO 4 2 69 87.1 1 day Example 3-19 CMC-NH 4 0.5 Mg(NO 3 ) 2 2 71 87 2 days Example 3-20 CMC-NH 4 0.5 Mg 3 (PO 4 ) 2 2 70 87.2 2 days Example 3-21 CMC-NH 4 0.5 AlCl 3 2 68 87.2 2 days Example 3-22 CMC-NH 4 0.5 AlPO 4 2 69 87.1 2 days Example 3-23 CMC-NH 4 2 Mg(NO 3 ) 2 3 69 87.3 2 days Example 3-24 CMC-NH 4 2 Mg 3 (PO 4 ) 2 3 68 87.1 2 days Example 3-25 CMC-NH 4 2 AlCl 3 3 68 87.2 2 days Example 3-26 CMC-NH 4 2 AlPO 4 3 69 87.3 3 days Example 3-27 CMC-NH 4 5 Mg(NO 3 ) 2 5 70 87.2 2 days Example 3-28 CMC-NH 4 5 Mg 3 (PO 4 ) 2 5 71 87.1 3 days Example 3-29 CMC-NH 4 5 AlCl 3 5 71 87 2 days Example 3-30 CMC-NH 4 5 AlPO 4 5 70 87.1 3 days Example 3-31 CMC-NH 4 0.1 Mg(NO 3 ) 2 0.1 68 87.1 15 hours Example 3-32 CMC-NH 4 0.1 Mg 3 (PO 4 ) 2 0.1 69 87 16 hours Example 3-33 CMC-NH 4 0.1 AlCl 3 0.1 71 87.2 16 hours Example 3-34 CMC-NH 4 0.1 AlPO 4 0.1 70 87.3 15 hours Example 3-35 CMC-NH 4 0.1 Mg(NO 3 ) 2 0.5 70 87.2 1 day Example 3-36 CMC-NH 4 0.1 Mg 3 (PO 4 ) 2 0.5 70 87.1 21 hours Example 3-37 CMC-NH 4 0.1 AlCl 3 0.5 70 87.1 1 day Example 3-38 CMC-NH 4 0.1 AlPO 4 0.5 71 87 1 day

由表3可知，當負極活性物質粒子中同時包含羧甲基纖維素的鹽、及包含鎂或鋁之金屬鹽時，至產生氣體為止的時間變長，而水系負極漿料的穩定性提升。又，羧甲基纖維素的鹽與包含鎂或鋁之金屬鹽的含量，若分別為0.1質量%以上，則能夠獲得充分的水系負極漿料的穩定性。又，相較於像實施例3-10～3-14這樣羧甲基纖維素的鹽少於金屬鹽的含量之實施例，在實施例3-1～3-4、3-15～3-26、3-35～3-38這樣羧甲基纖維素的鹽多於金屬鹽的含量之實施例中，至產生氣體為止的時間更增加。It can be seen from Table 3 that when both the salt of carboxymethyl cellulose and the metal salt of magnesium or aluminum are contained in the negative electrode active material particles, the time until the gas is generated becomes longer, and the stability of the aqueous negative electrode slurry is improved. Moreover, if the content of the carboxymethyl cellulose salt and the metal salt containing magnesium or aluminum is 0.1% by mass or more, sufficient stability of the aqueous negative electrode slurry can be obtained. In addition, compared with the examples in which the carboxymethyl cellulose salt is less than the metal salt content in the examples 3-10 to 3-14, in the examples 3-1 to 3-4, 3-15 to 3- 26. In the examples in which the salt of carboxymethyl cellulose is more than the content of the metal salt such as 3-35 to 3-38, the time until the gas is generated is further increased.

(實施例3-39～實施例3-43) 將羧甲基纖維素變更成聚丙烯酸(PAA)的鹽，並將金屬鹽的種類與金屬鹽的含量變更成如表4所示，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Example 3-39～Example 3-43) The carboxymethyl cellulose was changed to a salt of polyacrylic acid (PAA), and the type of metal salt and the content of the metal salt were changed as shown in Table 4. In addition, the secondary was prepared under the same conditions as in Example 1-2 Battery, and evaluate the cycle characteristics, initial efficiency and stability of the water-based negative electrode slurry.

將實施例3-39～實施例3-43的結果表示於表4中。再者，表中的「PAA-NH 4」，意指聚丙烯酸的銨鹽。 Table 4 shows the results of Example 3-39 to Example 3-43. Furthermore, "PAA-NH 4 "in the table means the ammonium salt of polyacrylic acid.

[表4] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； 濕式混合法 表4 PAA的鹽的種類 PAA的鹽的含量 (質量%) 金屬鹽 的種類 金屬鹽 的含量 (質量%) 容量 維持率 (%) 起始 效率 (%) 至產生氣體為止的時間 實施例3-39 PAA-NH 4 1 Mg(NO 3) 2 2 70 72 2天 實施例3-40 PAA-NH 4 1 Mg 3(PO 4) 2 2 69 87 2天 實施例3-41 PAA-NH 4 1 AlCl 3 2 71 87.1 2天 實施例3-42 PAA-NH 4 1 Al(NO 3) 3 2 70 87.2 2天 實施例3-43 PAA -NH 4 1 AlPO 4 2 71 87.1 2天 [Table 4] SiOx: x = 1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; Carbon material: average thickness 50nm half-value width 2.257°; crystallite 3.77nm; modification method: redox method; A>B; wet mixing method Table 4 Types of PAA salt PAA salt content (mass%) Types of metal salts Metal salt content (mass%) Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 3-39 PAA-NH 4 1 Mg(NO 3 ) 2 2 70 72 2 days Example 3-40 PAA-NH 4 1 Mg 3 (PO 4 ) 2 2 69 87 2 days Example 3-41 PAA-NH 4 1 AlCl 3 2 71 87.1 2 days Example 3-42 PAA-NH 4 1 Al(NO 3 ) 3 2 70 87.2 2 days Example 3-43 PAA -NH 4 1 AlPO 4 2 71 87.1 2 days

由表4可知，與使用了羧甲基纖維素的鹽的情況同樣地，當負極活性物質粒子中同時包含聚丙烯酸的鹽與包含鎂或鋁之金屬鹽時，至產生氣體為止的時間增加，而水系負極漿料的穩定性提升。It can be seen from Table 4 that, as in the case of using the salt of carboxymethyl cellulose, when the salt of polyacrylic acid and the metal salt of magnesium or aluminum are contained in the negative electrode active material particles, the time until the gas is generated increases. The stability of the aqueous negative electrode slurry is improved.

(比較例3-1) 在負極活性物質粒子的改質後，不使負極活性物質粒子含有聚丙烯酸的鹽、羧甲基纖維素的鹽、包含鎂之金屬鹽、及包含鋁之金屬鹽中的任一種鹽，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Comparative Example 3-1) After the modification of the negative electrode active material particles, the negative electrode active material particles are not made to contain any of polyacrylic acid salt, carboxymethyl cellulose salt, metal salt containing magnesium, and metal salt containing aluminum. The secondary battery was produced under the same conditions as in Example 1-2, and the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry were evaluated.

(比較例3-2～比較例3-7) 在負極活性物質粒子的改質後，使負極活性物質粒子僅含有聚丙烯酸的鹽或羧甲基纖維素的鹽，而不含有金屬鹽，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Comparative Example 3-2～Comparative Example 3-7) After the modification of the negative electrode active material particles, the negative electrode active material particles were made to contain only the salt of polyacrylic acid or the salt of carboxymethyl cellulose, but not the metal salt. In addition, the second was prepared under the same conditions as in Example 1-2. Secondary battery, and evaluate the cycle characteristics, primary efficiency and stability of the water-based negative electrode slurry.

(比較例3-8～比較例3-14) 在負極活性物質粒子的改質後，不使負極活性物質粒子含有聚丙烯酸的鹽或羧甲基纖維素的鹽，而使負極活性物質粒子僅含有金屬鹽，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Comparative Example 3-8～Comparative Example 3-14) After the modification of the negative electrode active material particles, the negative electrode active material particles were not made to contain the salt of polyacrylic acid or the salt of carboxymethyl cellulose, and the negative electrode active material particles were made to contain only the metal salt. The secondary battery was fabricated under the same conditions, and the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry were evaluated.

將比較例3-1～比較例3-14的結果表示於表5中。再者，表5中的「PAA-Li」，意指聚丙烯酸的鋰鹽。Table 5 shows the results of Comparative Example 3-1 to Comparative Example 3-14. In addition, "PAA-Li" in Table 5 means the lithium salt of polyacrylic acid.

[表5] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； 濕式混合法 表5 PAA的鹽或CMC的鹽的種類 PAA的鹽CMC的鹽的含量 (質量%) 金屬鹽 的種類 金屬鹽 的含量 (質量%) 容量 維持率 (%) 起始 效率 (%) 至產生氣體為止的時間 比較例3-1 － － － － 69 87.1 3小時 比較例3-2 PAA-Li 1 － － 68 87 3小時 比較例3-3 PAA-NH 4 1 － － 67 87.2 3小時 比較例3-4 PAA-Li 2 － － 69 87.1 3小時 比較例3-5 PAA-NH 4 2 － － 69 87 3小時 比較例3-6 CMC-NH 4 1 － － 68 87 3小時 比較例3-7 CMC-NH 4 2 － － 67 87.3 3小時 比較例3-8 － － Mg(NO 3) 2 2 69 87 6小時 比較例3-9 － － MgCl 2 2 68 87.1 6小時 比較例3-10 － － MgSO 4 2 67 87.2 6小時 比較例3-11 － － Mg 3(PO 4) 2 2 70 87.1 6小時 比較例3-12 － － AlCl 3 2 70 87.2 8小時 比較例3-13 － － Al(NO 3) 3 2 69 87.1 9小時 比較例3-14 － － AlPO 4 2 69 87.1 8小時 [Table 5] SiOx: x = 1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; Carbon material: average thickness 50nm half-value width 2.257°; crystallite 3.77nm; modification method: redox method; A>B; wet mixing method table 5 Types of PAA salt or CMC salt PAA salt CMC salt content (mass%) Types of metal salts Metal salt content (mass%) Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Comparative example 3-1 - - - - 69 87.1 3 hours Comparative example 3-2 PAA-Li 1 - - 68 87 3 hours Comparative example 3-3 PAA-NH 4 1 - - 67 87.2 3 hours Comparative example 3-4 PAA-Li 2 - - 69 87.1 3 hours Comparative example 3-5 PAA-NH 4 2 - - 69 87 3 hours Comparative example 3-6 CMC-NH 4 1 - - 68 87 3 hours Comparative example 3-7 CMC-NH 4 2 - - 67 87.3 3 hours Comparative example 3-8 - - Mg(NO 3 ) 2 2 69 87 6 hours Comparative example 3-9 - - MgCl 2 2 68 87.1 6 hours Comparative example 3-10 - - MgSO 4 2 67 87.2 6 hours Comparative example 3-11 - - Mg 3 (PO 4 ) 2 2 70 87.1 6 hours Comparative example 3-12 - - AlCl 3 2 70 87.2 8 hours Comparative example 3-13 - - Al(NO 3 ) 3 2 69 87.1 9 hours Comparative example 3-14 - - AlPO 4 2 69 87.1 8 hours

由比較例3-2～3-7可知，當使負極活性物質粒子僅含有聚丙烯酸的鹽或羧甲基纖維素的鹽時，至產生氣體為止的時間與比較例3-1相同，而無法獲得提升漿料的穩定性的功效。又，當使負極活性物質粒子僅含有金屬鹽時，為下述結果：雖然相較於比較例3-2～3-7，至產生氣體為止的時間更增加，但比表3、4所示的實施例差。It can be seen from Comparative Examples 3-2 to 3-7 that when the negative electrode active material particles contain only the salt of polyacrylic acid or the salt of carboxymethyl cellulose, the time until the gas is generated is the same as that of Comparative Example 3-1. Obtain the effect of improving the stability of the slurry. In addition, when the negative electrode active material particles were made to contain only the metal salt, the results were as follows: Although the time until gas generation was longer than that of Comparative Examples 3-2 to 3-7, it was higher than that shown in Tables 3 and 4. The embodiment is poor.

(實施例4-1) 將使負極活性物質粒子含有聚丙烯酸的鹽或羧甲基纖維素的鹽與金屬鹽的方法，由濕式混合法變更成使用Hosokawa Micron NOBILTA(R) NOB而實行的乾式混合法，此外則以與實施例1-2相同程序來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。具體而言，是對100g負極活性物質粒子加入1g的CMC-NH 4、2g的AlPO 4，並使用NOBILTA來實行處理(NOBILTA處理)30秒。 (Example 4-1) The method of making the negative electrode active material particles contain polyacrylic acid salt or carboxymethyl cellulose salt and metal salt was changed from the wet mixing method to Hosokawa Micron NOBILTA(R) NOB. In the dry mixing method, a secondary battery was fabricated in the same procedure as in Example 1-2, and the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry were evaluated. Specifically, 1 g of CMC-NH 4 and 2 g of AlPO 4 were added to 100 g of negative electrode active material particles, and NOBILTA was used to perform treatment (NOBILTA treatment) for 30 seconds.

(實施例4-2) 將使負極活性物質粒子含有聚丙烯酸的鹽或羧甲基纖維素的鹽與金屬鹽的方法，由濕式混合法變更成使用Hosokawa Micron NAUTA MIXER(R) DBX而實行的乾式混合法，此外則以與實施例1-2相同程序來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。具體而言，是對100g負極活性物質粒子加入1g的CMC-NH 4、2g的AlPO 4，並使用NOBILTA來實行混合1小時。 (Example 4-2) The method of making the negative electrode active material particles contain polyacrylic acid salt or carboxymethyl cellulose salt and metal salt was changed from the wet mixing method to Hosokawa Micron NAUTA MIXER(R) DBX. In addition, the same procedure as in Example 1-2 was used to fabricate a secondary battery, and the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry were evaluated. Specifically, 1 g of CMC-NH 4 and 2 g of AlPO 4 were added to 100 g of negative electrode active material particles, and NOBILTA was used for mixing for 1 hour.

將實施例4-1～4-2的結果表示於表6中。The results of Examples 4-1 to 4-2 are shown in Table 6.

[表6] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； 乾式混合法 表6 CMC的鹽的種類 CMC的鹽的含量 (質量%) 金屬鹽 的種類 金屬鹽 的含量 (質量%) 容量 維持率 (%) 起始 效率 (%) 至產生氣體為止的時間 實施例4-1 CMC-NH 4 1 AlPO 4 2 69 87.2 4天 實施例4-2 CMC-NH 4 1 AlPO 4 2 69 87 4天 [Table 6] SiOx: x=1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; Carbon material: average thickness 50nm half-value width 2.257°; crystallite 3.77nm; modification method: redox method; A>B; dry mixing method Table 6 Types of CMC salt CMC salt content (mass%) Types of metal salts Metal salt content (mass%) Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 4-1 CMC-NH 4 1 AlPO 4 2 69 87.2 4 days Example 4-2 CMC-NH 4 1 AlPO 4 2 69 87 4 days

當使用乾式混合法時，相較於使用濕式混合法的情況，至產生氣體為止的時間進一步增加。When the dry mixing method is used, the time until the gas is generated is further increased compared to the case of using the wet mixing method.

(實施例5-1～5-9) 改變矽化合物粒子的結晶性如表7所示，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。再者，可藉由原料的汽化溫度的變更、或矽化合物粒子生成後的熱處理，來控制矽化合物粒子中的結晶性。在實施例5-9中，雖然計算出半值寬為20°以上，但是這是使用解析軟體進行擬合(fitting)的結果，實質上未獲得峰。因此，實施例5-9的矽化合物，可謂實質上為非晶質。 (Examples 5-1 to 5-9) The crystallinity of the silicon compound particles was changed as shown in Table 7. In addition, a secondary battery was fabricated under the same conditions as in Example 1-2, and the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry were evaluated. Furthermore, the crystallinity in the silicon compound particles can be controlled by changing the vaporization temperature of the raw materials or the heat treatment after the silicon compound particles are formed. In Examples 5-9, although the half-value width was calculated to be 20° or more, this was a result of fitting using analysis software, and no peak was substantially obtained. Therefore, the silicon compound of Examples 5-9 can be said to be substantially amorphous.

[表7] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 改質方法：氧化還原法；A＞B； CMC-NH 4含量：1質量%；AlPO 4含量：2質量%；濕式混合法 表7 半值寬 (°) Si(111)微晶尺寸 (nm) 容量維持率 (%) 起始效率 (%) 至產生氣體為止的時間 實施例5-1 0.756 11.42 68 87 1天 實施例5-2 0.796 10.84 68 86.8 1天 實施例5-3 1.025 8.55 68 86.9 2天 實施例5-4 1.218 7.21 69 87 3天 實施例5-5 1.271 6.63 68 87.1 3天 實施例5-6 1.845 4.62 69 87 3天 實施例1-2 2.257 3.77 70 87.3 3天 實施例5-7 2.593 3.29 72 87.3 3天 實施例5-8 10.123 1.524 72 87.1 3天 實施例5-9 20.221 0 73 87.1 3天 [Table 7] SiOx: x = 1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; Carbon material: average thickness 50nm Modification method: redox method; A>B; CMC-NH 4 content: 1% by mass; AlPO 4 content: 2% by mass; wet mixing method Table 7 Half width (°) Si(111) crystallite size (nm) Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 5-1 0.756 11.42 68 87 1 day Example 5-2 0.796 10.84 68 86.8 1 day Example 5-3 1.025 8.55 68 86.9 2 days Example 5-4 1.218 7.21 69 87 3 days Example 5-5 1.271 6.63 68 87.1 3 days Example 5-6 1.845 4.62 69 87 3 days Example 1-2 2.257 3.77 70 87.3 3 days Example 5-7 2.593 3.29 72 87.3 3 days Example 5-8 10.123 1.524 72 87.1 3 days Example 5-9 20.221 0 73 87.1 3 days

尤其是半值寬為1.2°以上並且由Si(111)面所導致的微晶尺寸為7.5nm以下之低結晶性材料，可獲得較高的起始效率和容量維持率。In particular, low-crystallinity materials with a half-value width of 1.2° or more and a crystallite size of 7.5 nm or less caused by the Si(111) plane can obtain higher initial efficiency and capacity retention.

(實施例6-1) 將矽化合物設為矽和矽酸鋰區域的最大峰強度值A與源自上述SiO 2區域的峰強度值B的關係為A＜B，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。此時，在改質時藉由減少鋰的***量，來減少Li 2SiO 3的量，而縮小源自Li 2SiO 3的峰強度A。 (Example 6-1) The relationship between the maximum peak intensity value A of the silicon and lithium silicate region and the peak intensity value B derived from the above-mentioned SiO 2 region as the silicon compound is A<B, and the relationship with Example 1 -2 Make a secondary battery under the same conditions, and evaluate the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry. At this time, by reducing the amount of lithium inserted during the reforming, the amount of Li 2 SiO 3 is reduced, and the peak intensity A derived from Li 2 SiO 3 is reduced.

[表8] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法； CMC-NH 4含量：1質量%；AlPO 4含量：2質量%；濕式混合法 表8 A、B 容量維持率 (%) 起始效率 (%) 至產生氣體為止的時間 實施例6-1 A＜B 67 86.4 3天 實施例1-2 A＞B 70 87.3 3天 [Table 8] SiOx: x=1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; Carbon material: average thickness 50nm half-value width 2.257°; crystallite 3.77nm; modification method: redox method; CMC-NH 4 content: 1 mass%; AlPO 4 content: 2 mass%; wet mixing method Table 8 A, B Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 6-1 A＜B 67 86.4 3 days Example 1-2 A＞B 70 87.3 3 days

由表8可知，峰強度的關係為A＞B的情況，電池特性提升。It can be seen from Table 8 that when the relationship of peak intensity is A>B, the battery characteristics are improved.

(實施例7-1～7-6) 改變矽化合物粒子的中值粒徑如表9所示，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。 (Examples 7-1 to 7-6) The median particle size of the silicon compound particles was changed as shown in Table 9. In addition, the secondary battery was fabricated under the same conditions as in Example 1-2, and the cycle characteristics, primary efficiency, and stability of the aqueous negative electrode slurry were evaluated.

[表9] SiOx：x＝1；石墨(天然石墨：人造石墨＝5：5)； SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；碳材料：平均厚度50nm 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； CMC-NH 4含量：1質量%；AlPO 4含量：2質量%；濕式混合法 表9 中值粒徑 (μm) 容量維持率 (%) 起始效率 (%) 至產生氣體為止的時間 實施例7-1 0.5 67 87 2天 實施例7-2 1 68 87.1 3天 實施例7-3 3 69 87.2 3天 實施例1-2 8 70 87.3 3天 實施例7-4 10 71 87.3 4天 實施例7-5 15 71 87.4 4天 實施例7-6 20 71 87.1 4天 [Table 9] SiOx: x=1; graphite (natural graphite: artificial graphite=5:5); SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; carbon material: average thickness 50 nm half value Width 2.257°; crystallite 3.77nm; modification method: redox method; A>B; CMC-NH 4 content: 1 mass%; AlPO 4 content: 2 mass%; wet mixing method Table 9 Median particle size (μm) Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 7-1 0.5 67 87 2 days Example 7-2 1 68 87.1 3 days Example 7-3 3 69 87.2 3 days Example 1-2 8 70 87.3 3 days Example 7-4 10 71 87.3 4 days Example 7-5 15 71 87.4 4 days Example 7-6 20 71 87.1 4 days

若矽化合物的中值粒徑為3μm以上，則維持率和起始效率更提升。此被認為原因在於，矽化合物的每單位質量的表面積不會過大，而能夠縮小發生副反應的面積。另一方面，若中值粒徑為15μm以下，則在充電時粒子不易碎裂，而在充放電時不易生成由於新生表面導致的SEI(固體電解質界面)，因此能夠抑制可逆鋰的損耗。又，若矽系活性物質粒子的中值粒徑為15μm以下，則充電時的矽化合物粒子的膨脹量不會變大，因此能夠防止由於膨脹而導致的負極活性物質層的物理性破壞、電性破壞。If the median particle size of the silicon compound is 3 μm or more, the maintenance rate and initial efficiency are further improved. This is considered to be because the surface area per unit mass of the silicon compound is not too large, and the area where side reactions occur can be reduced. On the other hand, if the median particle size is 15 μm or less, the particles are less likely to be broken during charging, and SEI (solid electrolyte interface) due to the newly formed surface is less likely to be generated during charging and discharging, so the loss of reversible lithium can be suppressed. In addition, if the median diameter of the silicon-based active material particles is 15 μm or less, the swelling amount of the silicon compound particles during charging will not increase, so physical damage and electrical damage to the negative electrode active material layer due to swelling can be prevented. Sexual destruction.

(實施例8-1～8-4) 將被覆在矽系活性物質粒子表面上的碳材料的平均厚度變更成如表10所示，此外則以與實施例1-2相同條件來製作二次電池，並評估循環特性、初次效率及水系負極漿料的穩定性。碳材料的平均厚度，可藉由變更CVD條件來進行調整。 (Examples 8-1～8-4) The average thickness of the carbon material coated on the surface of the silicon-based active material particles was changed as shown in Table 10. In addition, the secondary battery was fabricated under the same conditions as in Example 1-2, and the cycle characteristics, primary efficiency, and water system were evaluated. Stability of negative electrode slurry. The average thickness of the carbon material can be adjusted by changing the CVD conditions.

[表10] SiOx：x＝1，D 50＝8μm；石墨(天然石墨：人造石墨＝5：5)：D 50＝20μm SiOx比例：20質量%；Li 2Si 2O 5、Li 2SiO 3；有碳材料 半值寬2.257°；微晶3.77nm；改質方法：氧化還原法；A＞B； CMC-NH 4含量：1質量%；AlPO 4含量：2質量%；濕式混合法 表10 平均厚度 (nm) 容量維持率 (%) 起始效率 (%) 至產生氣體為止的時間 實施例8-1 5 68 87 4天 實施例8-2 10 69 87.2 4天 實施例1-2 50 70 87.3 4天 實施例8-3 1000 70 88 4天 實施例8-4 5000 71 88.1 4天 [Table 10] SiOx: x=1, D 50 = 8 μm; graphite (natural graphite: artificial graphite = 5: 5): D 50 = 20 μm SiOx ratio: 20% by mass; Li 2 Si 2 O 5 , Li 2 SiO 3 ; Carbon material half-value width 2.257°; crystallite 3.77nm; modification method: redox method; A>B; CMC-NH 4 content: 1 mass%; AlPO 4 content: 2 mass%; wet mixing method Table 10 Average thickness (nm) Capacity maintenance rate (%) Initial efficiency (%) Time until gas is generated Example 8-1 5 68 87 4 days Example 8-2 10 69 87.2 4 days Example 1-2 50 70 87.3 4 days Example 8-3 1000 70 88 4 days Example 8-4 5000 71 88.1 4 days

由表10可知，碳層的膜厚為5nm以上時，導電性提升，因此能夠提升容量維持率和起始效率。另一方面，若碳層的膜厚為5000nm以下，則在電池設計上，能夠充分確保矽化合物粒子的量，因此電池容量不會下降。It can be seen from Table 10 that when the film thickness of the carbon layer is 5 nm or more, the conductivity is improved, and therefore the capacity retention rate and initial efficiency can be improved. On the other hand, if the film thickness of the carbon layer is 5000 nm or less, the battery design can sufficiently ensure the amount of silicon compound particles, so the battery capacity does not decrease.

(實施例9-1) 變更負極活性物質中的矽系活性物質粒子的質量比例，此外則以與實施例1-2相同條件來製作二次電池，並評估電池容量的增加率。 (Example 9-1) The mass ratio of the silicon-based active material particles in the negative electrode active material was changed. In addition, a secondary battery was produced under the same conditions as in Example 1-2, and the increase rate of the battery capacity was evaluated.

第5圖示出表示矽系活性物質粒子相對於負極活性物質的總量的比例與二次電池的電池容量的增加率的關係的圖表。第5圖中的A所示的曲線，示出在本發明的負極的負極活性物質中，當增加矽化合物粒子的比例時的電池容量的增加率。另一方面，第5圖中的B所示的曲線，示出當增加未摻雜鋰之矽化合物粒子的比例時的電池容量的增加率。由第5圖可知，如果矽化合物的比例成為6質量%以上，則電池容量的增加率變得比以往大，且體積能量密度特別顯著地增加。FIG. 5 shows a graph showing the relationship between the ratio of the silicon-based active material particles to the total amount of the negative electrode active material and the increase rate of the battery capacity of the secondary battery. The curve indicated by A in Fig. 5 shows the rate of increase in battery capacity when the proportion of silicon compound particles is increased in the negative electrode active material of the negative electrode of the present invention. On the other hand, the curve shown by B in Figure 5 shows the rate of increase in battery capacity when the proportion of silicon compound particles that are not doped with lithium is increased. It can be seen from Fig. 5 that if the proportion of the silicon compound becomes 6 mass% or more, the increase rate of the battery capacity becomes larger than before, and the volumetric energy density increases particularly significantly.

再者，本發明並不受限於上述實施形態。上述實施形態為例示，任何具有實質上與本發明的申請專利範圍所記載的技術思想相同的構成且發揮相同功效者，皆包含在本發明的技術範圍內。In addition, the present invention is not limited to the above-mentioned embodiment. The above-mentioned embodiment is an example, and any structure that has substantially the same structure and the same effect as the technical idea described in the scope of the patent application of the present invention is included in the technical scope of the present invention.

10:負極 11:負極集電體 12:負極活性物質層 20:層合薄膜型二次電池 21:捲繞電極體 22:正極引線 23:負極引線 24:密著薄膜 25:外裝構件 10: negative electrode 11: Negative current collector 12: Negative active material layer 20: Laminated film type secondary battery 21: Wound electrode body 22: positive lead 23: negative lead 24: Adhesive film 25: Exterior components

第1圖是表示包含本發明的負極活性物質之非水電解質二次電池用負極的構成的一例的剖面圖。 第2圖是在根據氧化還原法實行改質後由矽化合物粒子測定出來的 29Si-MAS-NMR波譜的一例。 第3圖是在根據熱摻雜法實行改質後由矽化合物粒子測定出來的 29Si-MAS-NMR波譜的一例。 第4圖是表示包含本發明的負極活性物質之鋰二次電池的構成例(層合薄膜型)的圖。 第5圖是表示矽系活性物質粒子相對於負極活性物質的總量的比例與二次電池的電池容量的增加率的關係的圖表。 Fig. 1 is a cross-sectional view showing an example of the structure of a negative electrode for a non-aqueous electrolyte secondary battery containing the negative electrode active material of the present invention. Figure 2 is an example of 29 Si-MAS-NMR spectra measured from silicon compound particles after modification by the oxidation-reduction method. Figure 3 is an example of 29 Si-MAS-NMR spectrum measured from silicon compound particles after modification by the thermal doping method. Fig. 4 is a diagram showing a configuration example (laminated film type) of a lithium secondary battery containing the negative electrode active material of the present invention. FIG. 5 is a graph showing the relationship between the ratio of the silicon-based active material particles to the total amount of the negative electrode active material and the increase rate of the battery capacity of the secondary battery.

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10:負極 11:負極集電體 12:負極活性物質層 10: negative electrode 11: Negative current collector 12: Negative active material layer

Claims (13)

一種負極，其具備負極活性物質層，該負極的特徵在於： 前述負極活性物質層具有負極活性物質，該負極活性物質包含負極活性物質粒子， 前述負極活性物質粒子含有矽化合物粒子，該矽化合物粒子包含矽化合物SiO x，其中，0.5≦x≦1.6； 前述矽化合物粒子含有鋰化合物； 前述負極活性物質粒子包含由聚丙烯酸的鹽和羧甲基纖維素的鹽中選出的至少一種鹽，且包含金屬鹽，該金屬鹽包含由鎂和鋁中選出的至少一種金屬， 相對於前述負極活性物質粒子的總量，由前述聚丙烯酸的鹽和前述羧甲基纖維素的鹽中選出的至少一種鹽的總量，在0.1質量%以上且5質量%以下的範圍內。 A negative electrode comprising a negative electrode active material layer, the negative electrode is characterized in that: the negative electrode active material layer has a negative electrode active material, the negative electrode active material contains negative electrode active material particles, the negative electrode active material particles contain silicon compound particles, the silicon compound particles Containing silicon compound SiO x , where 0.5≦x≦1.6; The aforementioned silicon compound particles contain a lithium compound; The aforementioned negative electrode active material particles contain at least one salt selected from a salt of polyacrylic acid and a salt of carboxymethyl cellulose, and A metal salt containing at least one metal selected from magnesium and aluminum, and at least one salt selected from the aforementioned polyacrylic acid salt and the aforementioned carboxymethylcellulose salt relative to the total amount of the aforementioned negative electrode active material particles The total amount is in the range of 0.1% by mass or more and 5% by mass or less. 如請求項1所述之負極，其中，由前述聚丙烯酸的鹽和前述羧甲基纖維素的鹽中選出的至少一種鹽是銨鹽。The negative electrode according to claim 1, wherein at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethyl cellulose is an ammonium salt. 如請求項1所述之負極，其中，相對於前述負極活性物質粒子的總量，前述包含由鎂和鋁中選出的至少一種金屬之金屬鹽的總量，在0.1質量%以上且5質量%以下的範圍內。The negative electrode according to claim 1, wherein the total amount of the metal salt containing at least one metal selected from magnesium and aluminum relative to the total amount of the negative electrode active material particles is 0.1% by mass or more and 5% by mass Within the following range. 如請求項1所述之負極，其中，前述包含由鎂和鋁中選出的至少一種金屬之金屬鹽是硝酸鹽、磷酸鹽、鹽酸鹽及硫酸鹽中的任一種。The negative electrode according to claim 1, wherein the aforementioned metal salt containing at least one metal selected from magnesium and aluminum is any one of nitrate, phosphate, hydrochloride, and sulfate. 如請求項1所述之負極，其中，前述負極活性物質粒子中包含的由前述聚丙烯酸的鹽和前述羧甲基纖維素的鹽中選出的至少一種鹽的以質量作為基準計的含量的合計量，小於前述負極活性物質粒子中包含的前述包含由鎂和鋁中選出的至少一種金屬之金屬鹽的以質量作為基準計的含量的合計量。The negative electrode according to claim 1, wherein the total content of at least one salt selected from the salt of polyacrylic acid and the salt of carboxymethylcellulose contained in the negative electrode active material particles on a mass basis The amount is smaller than the total amount of the metal salt containing at least one metal selected from magnesium and aluminum contained in the negative electrode active material particles on a mass basis. 如請求項1所述之負極，其中，前述負極活性物質粒子包含作為鋰化合物的Li 2Si 2O 5、Li 2SiO 3、Li 4SiO 4中的至少一種以上。 The negative electrode according to claim 1, wherein the negative electrode active material particles contain at least one of Li 2 Si 2 O 5 , Li 2 SiO 3 , and Li 4 SiO 4 as a lithium compound. 如請求項1所述之負極，其中，前述矽化合物粒子，其藉由使用Cu-Kα射線而實行的X射線繞射所獲得的由Si(111)結晶面所導致的繞射峰的半值寬(2θ)為1.2°以上，並且，對應於該結晶面之微晶尺寸為7.5 nm以下。The negative electrode according to claim 1, wherein the silicon compound particles are half-valued of the diffraction peak due to the Si(111) crystal plane obtained by X-ray diffraction using Cu-Kα rays The width (2θ) is 1.2° or more, and the crystallite size corresponding to the crystal plane is 7.5 nm or less. 如請求項1所述之負極，其中，在前述矽化合物粒子中，由 29Si-MAS-NMR波譜所獲得的在作為化學位移值的－60～－95ppm處所呈現的矽和矽酸鋰區域的最大峰強度值A、與在作為化學位移值的－96～－150ppm處所呈現的SiO 2區域的峰強度值B，滿足A＞B的關係。 The negative electrode according to claim 1, wherein, in the aforementioned silicon compound particles, the silicon and lithium silicate region exhibited at the chemical shift value of -60 to -95 ppm obtained from 29 Si-MAS-NMR spectroscopy The maximum peak intensity value A and the peak intensity value B of the SiO 2 region appearing at -96 to -150 ppm as the chemical shift value satisfy the relationship of A>B. 如請求項1所述之負極，其中，前述負極活性物質粒子的中值粒徑為3μm以上且15μm以下。The negative electrode according to claim 1, wherein the median diameter of the negative electrode active material particles is 3 μm or more and 15 μm or less. 如請求項1所述之負極，其中，前述負極活性物質粒子在表層部包含碳材料。The negative electrode according to claim 1, wherein the negative electrode active material particles include a carbon material in a surface layer portion. 如請求項1所述之負極，其中，前述碳材料的平均厚度為5nm以上且5000nm以下。The negative electrode according to claim 1, wherein the average thickness of the carbon material is 5 nm or more and 5000 nm or less. 如請求項1所述之負極，其中，前述負極進一步具有負極集電體，前述負極物質層被前述負極集電體支撐。The negative electrode according to claim 1, wherein the negative electrode further has a negative electrode current collector, and the negative electrode material layer is supported by the negative electrode current collector. 如請求項1～12中任一項所述之負極，其中，前述負極活性物質層進一步包含碳系活性物質。The negative electrode according to any one of claims 1 to 12, wherein the negative electrode active material layer further contains a carbon-based active material.
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