JP2000138063A - Nonaqueous electrolyte secondary battery - Google Patents

Nonaqueous electrolyte secondary battery

Info

Publication number
JP2000138063A
JP2000138063A JP10311909A JP31190998A JP2000138063A JP 2000138063 A JP2000138063 A JP 2000138063A JP 10311909 A JP10311909 A JP 10311909A JP 31190998 A JP31190998 A JP 31190998A JP 2000138063 A JP2000138063 A JP 2000138063A
Authority
JP
Japan
Prior art keywords
lithium
positive electrode
battery
carbon material
active material
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP10311909A
Other languages
Japanese (ja)
Inventor
Hiroshi Nakahara
浩 中原
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Japan Storage Battery Co Ltd
Original Assignee
Japan Storage Battery Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Japan Storage Battery Co Ltd filed Critical Japan Storage Battery Co Ltd
Priority to JP10311909A priority Critical patent/JP2000138063A/en
Publication of JP2000138063A publication Critical patent/JP2000138063A/en
Pending legal-status Critical Current

Links

Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10Energy storage using batteries

Abstract

PROBLEM TO BE SOLVED: To prevent reduction of a discharge capacity during using of the battery at high temperature, by providing a positive electrode containing a lithium manganese composite oxide and a negative electrode containing a carbon material having low crystalline carbon material on the surface of particles, and by using a nonaqueous electrolyte containing boron acid lithium tetrafluoride. SOLUTION: Spinel lithium manganete is used as lithium manganese composite oxide of a positive electrode active material, and a carbon material that has low crystalline carbon material on its surface and can store and release lithium can be used without restricting graphite. By using boron acid lithium tetrafluoride (LiBF4) as a support salt of a nonaqueous electrolyte, hydrogen fluoride(HF) is not generated even at high temperature, and elusion of Mn ions from spinel lithium manganete (LiMn2O4) as positive electrode active material is restrained. Thus, cost can be reduced during manufacture of a positive electrode, and reduction of charge/discharge cycle performance at high temperature can be restrained.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、非水電解質二次電
池に属する。
TECHNICAL FIELD The present invention relates to a non-aqueous electrolyte secondary battery.

【0002】[0002]

【従来の技術】近年、携帯用無線電話、携帯用パソコ
ン、携帯用ビデオカメラ等の電子機器が開発され、各種
電子機器が携帯可能な程度に小型化されている。それに
伴って、内蔵される電池としても、高エネルギー密度を
有し、且つ軽量なものが採用されている。そのような要
求を満たす典型的な電池は、特にリチウム金属やリチウ
ム合金等の活物質、又はリチウムイオンをホスト物質
(ここでホスト物質とは、リチウムイオンを吸蔵及び放
出できる物質をいう。)である炭素に吸蔵させたリチウ
ムインターカレーション化合物を負極材料とし、LiC
lO4、LiPF6等のリチウム塩を溶解した非プロトン
性の有機溶媒を電解液とする非水電解質二次電池であ
る。
2. Description of the Related Art In recent years, electronic devices such as a portable radio telephone, a portable personal computer, and a portable video camera have been developed, and various electronic devices have been reduced in size to be portable. Along with this, a battery having a high energy density and a light weight is also adopted as a built-in battery. A typical battery that satisfies such a requirement is an active material such as lithium metal or lithium alloy, or a host material containing lithium ions (here, a host material refers to a material that can occlude and release lithium ions). Lithium intercalation compound occluded in a certain carbon is used as a negative electrode material, and LiC
This is a non-aqueous electrolyte secondary battery using an aprotic organic solvent in which a lithium salt such as 10 4 or LiPF 6 is dissolved as an electrolyte.

【0003】この非水電解質二次電池は、上記の負極材
料をその支持体である負極集電体に保持してなる負極
板、リチウムコバルト複合酸化物のようにリチウムイオ
ンと可逆的に電気化学反応をする正極活物質をその支持
体である正極集電体に保持してなる正極板、電解液を保
持するとともに負極板と正極板との間に介在して両極の
短絡を防止するセパレータからなっている。
This non-aqueous electrolyte secondary battery has a negative electrode plate in which the above-mentioned negative electrode material is held on a negative electrode current collector as a support, and a reversible electrochemical reaction with lithium ions such as a lithium-cobalt composite oxide. The positive electrode plate, which holds the positive electrode active material that reacts on the positive electrode current collector that is the support, from the separator that holds the electrolytic solution and intervenes between the negative electrode plate and the positive electrode plate to prevent a short circuit between the two electrodes Has become.

【0004】そして、上記正極板、セパレータ及び負極
板は、いずれも薄いシートないし箔状に成形されたもの
を順に積層、又は螺旋状に巻いて、金属製の電池容器や
気密構造を有する金属ラミネート樹脂フィルムからなる
電池容器に収納される。
The above-mentioned positive electrode plate, separator and negative electrode plate are all formed in the form of a thin sheet or foil and laminated or spirally wound to form a metal battery container or a metal laminate having an airtight structure. It is stored in a battery container made of a resin film.

【0005】また、前記非水電解質電池では、従来、正
極活物質としては、充放電性能や安全性の面から、主に
コバルト酸リチウムが使用されている。しかしながら、
含有元素のコバルトは、原産地が限られ、産出量も少な
いことから高価である。さらに、コバルトは戦略物質で
あり、これの原産地の政情や先物取引等の影響で価格の
変動が大きく、コバルト酸リチウムのコストに大きく影
響する。
[0005] In the non-aqueous electrolyte battery, lithium cobalt oxide has conventionally been mainly used as a positive electrode active material from the viewpoint of charge / discharge performance and safety. However,
The elemental element cobalt is expensive because its place of origin is limited and its yield is small. Further, cobalt is a strategic substance, and its price fluctuates greatly due to the political situation of its place of origin, futures transactions, and the like, which greatly affects the cost of lithium cobalt oxide.

【0006】コバルト酸リチウムに代わる正極活物質と
してニッケル酸リチウムの利用が検討されている。ニッ
ケル酸リチウムは単価が安く、重量当たりの放電容量が
大きいことから、電池のコストダウンと高容量化の面か
ら次期非水電解質電池の正極活物質として期待されてい
る。しかし、コバルト酸リチウムが分解を始める温度と
比較すると、ニッケル酸リチウムの方が低い温度から分
解・発熱するため安全性の面で解決すべき問題が残って
いる。
The use of lithium nickelate as a positive electrode active material instead of lithium cobaltate has been studied. Since lithium nickelate has a low unit price and a large discharge capacity per weight, lithium nickelate is expected as a positive electrode active material for the next nonaqueous electrolyte battery from the viewpoint of cost reduction and high capacity of the battery. However, when compared with the temperature at which lithium cobaltate starts to decompose, lithium nickelate decomposes and generates heat from a lower temperature, so that there remains a problem to be solved in terms of safety.

【0007】そこで、コバルト酸リチウムやニッケル酸
リチウムと比較して、コストと安全性の面から、リチウ
ムマンガン複合酸化物が有望であると考えられる。しか
しながら、従来のLiPF6を溶解した電解液を用いた
場合、高温下において、リチウムマンガン複合酸化物か
らMnイオンが電解液に溶出して、活物質の結晶構造が
変化してしまうとともに、充放電性能が低下するという
問題がある。
[0007] Therefore, compared with lithium cobaltate and lithium nickelate, lithium manganese composite oxides are considered to be promising in terms of cost and safety. However, when a conventional electrolytic solution in which LiPF 6 is dissolved is used, Mn ions are eluted from the lithium manganese composite oxide into the electrolytic solution at a high temperature, and the crystal structure of the active material is changed. There is a problem that performance is reduced.

【0008】この問題は、電池の実使用時の環境温度を
考えると、二次電池としては致命的なものであると考え
られる。実使用時に電池が高温になる例としては、充電
時における充電器の発熱による電池の温度上昇や、ノー
ト型パソコンなど電池を装着している機器の発熱による
電池の温度上昇などが考えられる。
[0008] This problem is considered to be fatal for a secondary battery in view of the environmental temperature during actual use of the battery. Examples of the case where the temperature of the battery becomes high during actual use include an increase in the temperature of the battery due to the heat generated by the charger during charging, and an increase in the temperature of the battery due to the heat generated by a device equipped with the battery such as a notebook computer.

【0009】前記のリチウムマンガン複合酸化物の分解
反応のメカニズムについて、現在のところ、詳細なこと
は明らかになっていないが、高温下で電解液の支持塩に
用いられているLiPF6が分解してフッ化水素(H
F)が発生し、これによってスピネルマンガン酸リチウ
ムからMnイオンが溶出するものと考えられる。そこで
高温下においてもフッ化水素(HF)を発生しない支持
塩を選択すれば、リチウムマンガン複合酸化物からのM
nイオンの溶出を抑制できることになる。そこで、電解
液の支持塩として、高温下でも分解しない四フッ化ホウ
素酸リチウム(LiBF4)を使用することが考えられ
る。
Although the details of the mechanism of the decomposition reaction of the lithium manganese composite oxide have not been clarified at present, LiPF 6 used as a supporting salt of the electrolytic solution is decomposed at a high temperature. Hydrogen fluoride (H
It is considered that F) occurs and Mn ions elute from lithium spinel manganate. Therefore, by selecting a supporting salt that does not generate hydrogen fluoride (HF) even at high temperatures, M
The elution of n ions can be suppressed. Therefore, it is conceivable to use lithium tetrafluoroborate (LiBF 4 ), which does not decompose even at a high temperature, as a supporting salt of the electrolytic solution.

【0010】いっぽう、非水電解質電池の負極にはグラ
ファイト等の炭素材料が用いられている。炭素材料から
なる負極は、LiPF6を溶解した電解液中では、炭素
材料の表面に保護皮膜が形成され、充放電サイクルを繰
り返してもサイクルの進行にともなう放電容量の低下は
少ない。ところが、リチウムマンガン複合酸化物からの
Mnイオンの溶出を抑制するために四フッ化ホウ素酸リ
チウム(LiBF4) を溶解した電解液を用いた場
合、負極活物質である炭素材料表面には保護皮膜が形成
されず、炭素材料表面で電解液溶媒が分解し、負極の炭
素材料の充放電性能が低下してしてしまうという問題が
あった。
On the other hand, a carbon material such as graphite is used for a negative electrode of a nonaqueous electrolyte battery. In a negative electrode made of a carbon material, a protective film is formed on the surface of the carbon material in an electrolytic solution in which LiPF 6 is dissolved, and the discharge capacity does not decrease much with the progress of the charge / discharge cycle even if the charge / discharge cycle is repeated. However, when an electrolytic solution in which lithium tetrafluoroborate (LiBF 4 ) is dissolved is used to suppress the elution of Mn ions from the lithium manganese composite oxide, a protective film is formed on the surface of the carbon material as the negative electrode active material. Is not formed, and the electrolyte solvent decomposes on the surface of the carbon material, resulting in a problem that the charge / discharge performance of the carbon material of the negative electrode is reduced.

【0011】[0011]

【発明が解決しようとする課題】そこで、高温下におい
てもフッ化水素(HF)を発生しない支持塩として四フ
ッ化ホウ素酸リチウム(LiBF4)を使用することに
よって、正極活物質であるリチウムマンガン複合酸化物
からのMnイオンの溶出を抑制すると同時に、負極活物
質である炭素材料の表面で電解液が分解しないような非
水電解質二次電池が望まれていた。本発明は、いくつか
の手段を組合せることによって、正極活物質にリチウム
マンガン複合酸化物を用いた場合でも、高温下における
電池の使用時に放電容量が低下する問題を解決するもの
である。
Therefore, by using lithium tetrafluoroborate (LiBF 4 ) as a supporting salt which does not generate hydrogen fluoride (HF) even at high temperatures, lithium manganese which is a positive electrode active material is produced. A non-aqueous electrolyte secondary battery in which the elution of Mn ions from the composite oxide is suppressed and the electrolyte does not decompose on the surface of the carbon material as the negative electrode active material has been desired. The present invention solves the problem that the discharge capacity decreases when the battery is used at a high temperature even when a lithium manganese composite oxide is used as the positive electrode active material by combining several means.

【0012】[0012]

【課題を解決するための手段】本発明は、リチウムマン
ガン複合酸化物を含む正極と、リチウムイオンの吸蔵放
出が可能で粒子表面に低結晶性炭素材料を備えた炭素材
料を含む負極とを備えた非水電解質電池において、四フ
ッ化ホウ素酸リチウム(LiBF4)を溶解した非水電
解液を使用することを特徴とするものである。
SUMMARY OF THE INVENTION The present invention comprises a positive electrode containing a lithium manganese composite oxide, and a negative electrode containing a carbon material capable of inserting and extracting lithium ions and having a low crystalline carbon material on the particle surface. A non-aqueous electrolyte battery characterized by using a non-aqueous electrolyte in which lithium tetrafluoroborate (LiBF 4 ) is dissolved.

【0013】なお、低結晶性炭素材料には、リチウムイ
オンが吸蔵放出することはないので、負極活物質として
は働かない。
The low-crystalline carbon material does not function as a negative electrode active material because lithium ions are not absorbed and released.

【0014】また、負極活物質としての炭素材料粒子の
表面への低結晶性炭素材料の取り付け方は、活物質とし
ての炭素材料粒子の表面を、低結晶性炭素材料で完全に
覆ってもよいし、一部を覆ってもよい。例えば、負極活
物質に黒鉛を使用する場合、黒鉛は炭素六員環が網目状
に広がった層状構造をとるため、エッジ面とベーサル面
をもち、電解液溶媒はエッジ面でのみ分解される。その
ため黒鉛のエッジ面が低結晶性炭素材料で覆われていさ
えすれば、電解液溶媒の分解を防止することができるも
のである。
The method of attaching the low-crystalline carbon material to the surface of the carbon material particles as the negative electrode active material may be such that the surface of the carbon material particles as the active material is completely covered with the low-crystalline carbon material. Then, it may be partially covered. For example, when graphite is used as the negative electrode active material, graphite has an edge surface and a basal surface because the carbon has a layered structure in which a six-membered carbon ring is spread in a network, and the electrolyte solvent is decomposed only at the edge surface. Therefore, as long as the edge surface of the graphite is covered with the low-crystalline carbon material, the decomposition of the electrolyte solvent can be prevented.

【0015】[0015]

【発明の実施の形態】以下に、本発明の実施の形態を、
実施例にもとづき図面を参照して説明する。
DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
An embodiment will be described with reference to the drawings.

【0016】[0016]

【実施例】[実施例1]本発明になる非水電解質二次電
池の一実施例として、巻回した極板群を備えた角型非水
電解質二次電池を作製した。正極は、結着剤であるポリ
フッ化ビニリデン6重量部と導電剤であるアセチレンブ
ラック3重量部と活物質であるスピネルマンガン酸リチ
ウム(LiMn24)91重量部に溶媒としてのN−メ
チルピロリドンを適宜加えて混合したペーストを、乾燥
後の塗工重量が2.22g/100cm2となるように
正極集電体である20μmのアルミニウム箔の上に塗布
・乾燥し、厚さが150μmになるようにプレス成形
し、幅24mmに切断することによって作製した。ただ
し、リード取付け部分には正極合剤層を塗布しなかっ
た。
[Example 1] As an example of a non-aqueous electrolyte secondary battery according to the present invention, a rectangular non-aqueous electrolyte secondary battery including a wound electrode plate group was manufactured. The positive electrode was composed of 6 parts by weight of polyvinylidene fluoride as a binder, 3 parts by weight of acetylene black as a conductive agent, 91 parts by weight of lithium spinel manganate (LiMn 2 O 4 ) as an active material, and N-methylpyrrolidone as a solvent. Is applied and dried on a 20 μm aluminum foil serving as a positive electrode current collector so that the coating weight after drying is 2.22 g / 100 cm 2, and the paste is dried to a thickness of 150 μm. By pressing and cutting to a width of 24 mm. However, the positive electrode mixture layer was not applied to the lead attachment portion.

【0017】負極は、表面に全重量に対して15wt%
に相当する低結晶性炭素を備えた黒鉛92重量部とポリ
フッ化ビニリデン8重量部との混合物にN−メチルピロ
リドンを適宜加えて混合したペーストを、塗工重量が
1.20g/100cm2となるように負極集電体であ
る14μmの銅箔の上に塗布・乾燥し、厚さが180μ
mになるようにプレス成形し、幅26mmに切断するこ
とによって作製した。
The surface of the negative electrode is 15 wt% based on the total weight.
A paste obtained by appropriately adding N-methylpyrrolidone to a mixture of 92 parts by weight of graphite having low crystallinity carbon and 8 parts by weight of polyvinylidene fluoride to give a coating weight of 1.20 g / 100 cm 2 Is applied and dried on a 14 μm copper foil as a negative electrode current collector, and has a thickness of 180 μm.
m, and formed by cutting to a width of 26 mm.

【0018】なお、低結晶性炭素は黒鉛の表面に、次の
方法によって取り付けた。黒鉛粉末をのせた石英板製ホ
ルダーをパイレックスガラス製反応管の中に入れ、反応
管を外部から800℃に加熱しながら、この反応管中に
アルゴンとプロパンの混合ガスを供給し、プロパンガス
を熱分解して、黒鉛粒子の表面に低結晶性炭素を堆積さ
せた。
The low-crystalline carbon was attached to the surface of graphite by the following method. A quartz plate holder on which graphite powder is placed is placed in a Pyrex glass reaction tube, and a mixed gas of argon and propane is supplied into the reaction tube while heating the reaction tube to 800 ° C. from outside, and propane gas is supplied. By pyrolysis, low crystalline carbon was deposited on the surface of the graphite particles.

【0019】セパレータとしては、厚さ25μm、幅2
8mmのポリエチレン微多孔膜を使用した。前記正極、
セパレータおよび負極を積層し巻回した後、厚さ0.3
mm、内寸22×34×8mmの鉄製本体の表面に5μ
mのニッケルメッキを施した電池容器に収納して、蓋を
レーザー溶接した。これに、エチレンカーボネート(E
C):ジエチルカーボネート(DEC)=4:6(体積
比)の非水溶媒にLiBF4を1mol/l溶解した電
解液を注液して封口し、公称容量600mAhの非水電
解質二次電池を試作した。
The separator has a thickness of 25 μm and a width of 2 μm.
An 8 mm polyethylene microporous membrane was used. The positive electrode,
After laminating and winding the separator and the negative electrode, a thickness of 0.3
mm, 5μ on the surface of an iron body of 22 × 34 × 8mm
m, and the lid was laser-welded. In addition, ethylene carbonate (E
C): An electrolyte obtained by dissolving 1 mol / l of LiBF 4 in a non-aqueous solvent of diethyl carbonate (DEC) = 4: 6 (volume ratio) was injected and sealed, and a non-aqueous electrolyte secondary battery having a nominal capacity of 600 mAh was obtained. Prototype made.

【0020】[比較例1]負極活物質として、表面に低
結晶性炭素材料を備えていない黒鉛を用いた以外は、実
施例1と同様の非水電解質二次電池を試作した。
Comparative Example 1 A non-aqueous electrolyte secondary battery similar to that of Example 1 was produced as a trial except that graphite having no low-crystalline carbon material on its surface was used as a negative electrode active material.

【0021】[比較例2]電解液として、エチレンカー
ボネート(EC):ジエチルカーボネート(DEC)=
4:6(体積比)の非水溶媒にLiPF6を1mol/
l溶解した溶液を使用した以外は、実施例1と同様の非
水電解質二次電池を試作した。
Comparative Example 2 As an electrolytic solution, ethylene carbonate (EC): diethyl carbonate (DEC) =
LiPF 6 in a nonaqueous solvent of 4: 6 (volume ratio) at 1 mol /
A non-aqueous electrolyte secondary battery similar to that of Example 1 was produced as a trial except that a solution in which 1 was dissolved was used.

【0022】本発明になる実施例1の非水電解質二次電
池および比較例1および比較例2の非水電解質二次電池
を、つぎの条件で500サイクルの充放電を繰り返し
た。
The nonaqueous electrolyte secondary battery of Example 1 and the nonaqueous electrolyte secondary batteries of Comparative Examples 1 and 2 according to the present invention were repeatedly charged and discharged for 500 cycles under the following conditions.

【0023】充電:60℃、600mA定電流で4.1
Vまで、さらに4.1V定電圧で、合計3時間。
Charge: 4.1 at 60 ° C. and 600 mA constant current
Up to V and a constant voltage of 4.1 V for a total of 3 hours.

【0024】放電:60℃、600mA定電流で2.7
5Vまで。
Discharge: 2.7 at 60 ° C. and 600 mA constant current
Up to 5V.

【0025】充放電サイクルの進行にともなう放電容量
の推移を図1に示す。図1において、Aは実施例1の電
池、Bは比較例1になる電池、Cは比較例2になる電池
の、充放電サイクル数と放電容量の関係を示す。
FIG. 1 shows the transition of the discharge capacity as the charge / discharge cycle progresses. In FIG. 1, A shows the relationship between the number of charge / discharge cycles and the discharge capacity of the battery of Example 1, B shows the battery of Comparative Example 1, and C shows the battery of Comparative Example 2.

【0026】図1において、本発明になる実施例1の電
池(A)では、充放電サイクル数によって放電容量はほ
とんど変化しなかったのに対し、比較例1の電池(B)
においては、充放電サイクル初期から電池の放電容量が
小さく、また、比較例2の電池(C)では、充放電サイ
クル数が増加するにしたがって放電容量はかなり減少し
ていることが示された。
In FIG. 1, in the battery (A) of Example 1 according to the present invention, the discharge capacity hardly changed depending on the number of charge / discharge cycles, whereas in the battery (B) of Comparative Example 1
Shows that the discharge capacity of the battery was small from the beginning of the charge / discharge cycle, and that in the battery (C) of Comparative Example 2, the discharge capacity was considerably reduced as the number of charge / discharge cycles was increased.

【0027】比較例1の電池(B)においては、負極活
物質として表面に低結晶性炭素材料を備えていない黒鉛
を用い、支持塩としてLiBF4を用いたために、黒鉛
の表面に電解質溶媒の分解生成物であると考えられる化
合物層が形成され、黒鉛の充放電が困難なものとなっ
て、充放電サイクル初期から電池の放電容量が小さくな
ったものと考えられる。
In the battery (B) of Comparative Example 1, graphite having no low-crystalline carbon material on its surface was used as a negative electrode active material, and LiBF 4 was used as a supporting salt. It is considered that a compound layer considered to be a decomposition product was formed, making it difficult to charge and discharge graphite, and the discharge capacity of the battery was reduced from the beginning of the charge and discharge cycle.

【0028】さらに、500サイクルの充放電試験が終
了した電池を解体して、電解液中のMnイオンの定量分
析をおこなったところ、表1のような結果が得られた。
Further, the battery after completion of the charge / discharge test of 500 cycles was disassembled, and quantitative analysis of Mn ions in the electrolytic solution was performed. The results shown in Table 1 were obtained.

【0029】[0029]

【表1】 すなわち、本発明になる実施例1においては、電池を高
温下において充放電した場合、正極活物質からのMnイ
オンの溶出が抑制されていることがわかる。その理由
は、本発明になる実施例1の電池では、支持塩として四
フッ化ホウ素酸リチウム(LiBF4)を用いたために
高温下においてもフッ化水素(HF)を発生せず、正極
活物質であるスピネルマンガン酸リチウム(LiMn2
4)からのMnイオンの溶出が抑制されたものと考え
られる。
[Table 1] That is, in Example 1 according to the present invention, when the battery was charged and discharged at a high temperature, the elution of Mn ions from the positive electrode active material was suppressed. The reason is that, in the battery of Example 1 according to the present invention, since lithium tetrafluoroborate (LiBF4) was used as the supporting salt, hydrogen fluoride (HF) was not generated even at a high temperature, and the positive electrode active material was not used. A certain spinel lithium manganate (LiMn 2
It is considered that the elution of Mn ions from O 4 ) was suppressed.

【0030】すなわち、本発明の最大の効果は、正極活
物質には原料費が低価格であるスピネルマンガン酸リチ
ウムのようなリチウムマンガン複合酸化物を用いること
によって、正極製造時のコストダウンを可能とし、さら
に、リチウムマンガン複合酸化物を正極材料に用いた非
水電解質電池の高温下における充放電サイクル性能の低
下を抑制できるところにある。
That is, the greatest effect of the present invention is that, by using a lithium manganese composite oxide such as spinel lithium manganate, which has a low raw material cost, as the positive electrode active material, the cost can be reduced during the production of the positive electrode. Further, the present invention can suppress a decrease in charge / discharge cycle performance of a nonaqueous electrolyte battery using a lithium manganese composite oxide as a positive electrode material at a high temperature.

【0031】なお、本発明において使用する正極活物質
としてのリチウムマンガン複合酸化物は、実施例で述べ
たスピネルマンガン酸リチウムに限定されるものではな
く、この化合物の結晶中においてマンガン原子の占める
格子位置を少量のコバルト、ニッケル、アルミニウム、
クロム、鉄、マグネシウム、カルシウムなどの原子で置
換したものでもいし、LixMn24やLixMnO2
などの各種リチウムマンガン複合酸化物も使用可能であ
る。正極活物質として特に好ましくは、一般式ががLi
XMn24(0.8≦X≦1.2)で表わされるリチウ
ムマンガン複合酸化物である。
The lithium manganese composite oxide used as the positive electrode active material in the present invention is not limited to the lithium spinel manganese oxide described in the examples, and the lattice occupied by manganese atoms in the crystal of this compound is not limited. Move the position to a small amount of cobalt, nickel, aluminum,
It may be replaced by an atom such as chromium, iron, magnesium, calcium or the like, and may be LixMn 2 O 4 or LixMnO 2
And various lithium manganese composite oxides can also be used. Particularly preferably as the positive electrode active material, the general formula is Li
It is a lithium manganese composite oxide represented by XMn 2 O 4 (0.8 ≦ X ≦ 1.2).

【0032】また、負極活物質としては、実施例で述べ
た黒鉛に限定されるものではなく、表面に低結晶性炭素
材料を備えた、リチウムを吸蔵放出可能な炭素材料であ
れば種々の炭素材料が使用可能である。
The negative electrode active material is not limited to the graphite described in the embodiment, but may be any carbon material having a low crystalline carbon material on its surface and capable of inserting and extracting lithium. Material is available.

【0033】また、セパレータとしては、実施例で述べ
たポリエチレン微多孔膜以外にも、ポリプロピレン微多
孔膜などのポリオレフィン微多孔膜を、単独であるいは
2種類以上組み合わせて使用することもできる。
As the separator, a polyolefin microporous membrane such as a polypropylene microporous membrane other than the polyethylene microporous membrane described in the examples may be used alone or in combination of two or more.

【0034】電解液の非水溶媒としては、エチレンカー
ボネート(EC)とジエチルカーボネート(DEC)と
の混合溶液を用いているが、これに限定されるものでは
なく、エチレンカーボネート、プロピレンカーボネー
ト、ジメチルカーボネート、ジエチルカーボネート、γ
− ブチロラクトン、スルホラン、ジメチルスルホキシ
ド、アセトニトリル、ジメチルホルムアミド、ジメチル
アセトアミド、1,2−ジメトキシエタン、1,2−ジ
エトキシエタン、テトラヒドロフラン、2−メチルテト
ラヒドロフラン、ジオキソラン、メチルアセテート等の
極性溶媒を、単独でもしくはこれらの混合物を使用して
もよい。
As the non-aqueous solvent for the electrolytic solution, a mixed solution of ethylene carbonate (EC) and diethyl carbonate (DEC) is used, but the present invention is not limited to this. Ethylene carbonate, propylene carbonate, dimethyl carbonate , Diethyl carbonate, γ
A polar solvent such as butyrolactone, sulfolane, dimethylsulfoxide, acetonitrile, dimethylformamide, dimethylacetamide, 1,2-dimethoxyethane, 1,2-diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, dioxolane, methyl acetate, etc. Alternatively, a mixture thereof may be used.

【0035】なお、これらの非水溶媒の中では、エチレ
ンカーボネート、プロピレンカーボネート、ジメチルカ
ーボネート、ジエチルカーボネートを含んでいる溶媒が
好ましい。特にエチレンカーボネート、プロピレンカー
ボネートを含んでいると、電池を高温放置した場合の、
電解液溶媒の酸化分解が抑制され、電池のふくれを防止
することができる。
Among these non-aqueous solvents, a solvent containing ethylene carbonate, propylene carbonate, dimethyl carbonate and diethyl carbonate is preferable. In particular, when ethylene carbonate and propylene carbonate are included, when the battery is left at high temperatures,
Oxidative decomposition of the electrolyte solution solvent is suppressed, and blistering of the battery can be prevented.

【0036】また、電解質として、リチウムイオン導電
性固体高分子電解質膜を使用することもできる。この場
合、高分子中に含有させる電解液と、固体高分子電解質
膜の細孔中に含有させる電解液との電解液溶媒や支持塩
の濃度が異なっていてもよい。
Further, as the electrolyte, a lithium ion conductive solid polymer electrolyte membrane can be used. In this case, the concentrations of the electrolyte solvent and the supporting salt may be different between the electrolyte contained in the polymer and the electrolyte contained in the pores of the solid polymer electrolyte membrane.

【0037】なお、本発明実施例において、電池容器と
して金属製のものを用いたが、発電要素をたとえば薄い
シート状から形成されたソフトケースに収納してもよ
く、この場合、気密性に優れかつシーリング工程の煩雑
さを解消することができ、もって安価な製造、軽量化が
可能となる。しかも、この単電池、又は複数個の単電池
をたとえばハードプラスチックなどのハードケースに収
納することによって単電池には備わっていない機械強度
を補うことができる。加えて、単電池が気密性に優れる
ため、従来のようにハードケース自体の気密性を問題に
することがない。それゆえに、ワンタッチ式の組立構造
とすることができるため、電池パックの製造を極めて容
易にすることができる。さらに、電池収納容器には、イ
ンサート成形された外部機器接続用の端子が形成されて
いるので、なお一層のこと製造工程の容易化並びに製造
コストの削減ができる。
In the embodiment of the present invention, the battery case is made of metal. However, the power generating element may be housed in a soft case formed of a thin sheet, for example, and in this case, the airtightness is excellent. In addition, the complexity of the sealing step can be eliminated, so that inexpensive manufacturing and weight reduction can be achieved. In addition, by storing the single cell or a plurality of single cells in a hard case made of, for example, hard plastic, it is possible to supplement mechanical strength not provided in the single cell. In addition, since the cells have excellent airtightness, the airtightness of the hard case itself does not matter as in the related art. Therefore, since a one-touch assembly structure can be provided, the manufacture of the battery pack can be extremely facilitated. Furthermore, since the terminal for connecting external equipment formed by insert molding is formed in the battery housing, the manufacturing process can be further simplified and the manufacturing cost can be further reduced.

【0038】[0038]

【発明の効果】本発明になる非水電解質二次電池は、正
極活物質にリチウムマンガン複合酸化物、負極材料に粒
子表面に低結晶性炭素材料を備えた炭素材料、電解液支
持塩として四フッ化ホウ素酸リチウム(LiBF4)を
用いることによって、高温下において充放電サイクルを
繰りかえした場合においても放電容量の低下が少なく、
充放電性能に優れ、しかも軽量かつ安全性に優れた非水
電解質二次電池を提供することが可能である。
The non-aqueous electrolyte secondary battery according to the present invention comprises a lithium manganese composite oxide as a positive electrode active material, a carbon material having a low crystalline carbon material on the particle surface as a negative electrode material, and a four-dimensional electrolyte supporting salt. By using lithium fluoroborate (LiBF 4 ), even when charge and discharge cycles are repeated at a high temperature, a decrease in discharge capacity is small,
It is possible to provide a non-aqueous electrolyte secondary battery which is excellent in charge / discharge performance, lightweight, and excellent in safety.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明になる実施例1の電池、比較例1及び比
較例2電池の、充放電サイクル数と放電容量の関係を示
す図。
FIG. 1 is a diagram showing the relationship between the number of charge / discharge cycles and the discharge capacity of the battery of Example 1 and Comparative Example 1 and Comparative Example 2 batteries according to the present invention.

───────────────────────────────────────────────────── フロントページの続き Fターム(参考) 5H003 AA04 BB01 BB02 BB04 BB05 BB12 BC01 BC05 BC06 BD03 5H014 AA02 AA06 EE01 EE08 EE10 HH01 5H029 AJ05 AJ07 AK03 AL06 AL07 AL08 AM01 AM02 AM03 AM05 AM07 BJ02 BJ14 DJ09 DJ16 DJ17 HJ01  ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference)

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】リチウムマンガン複合酸化物を含む正極
と、リチウムイオンの吸蔵放出が可能で粒子表面に低結
晶性炭素材料を備えた炭素材料を含む負極とを備え、四
フッ化ホウ素酸リチウム(LiBF4)を含む非水電解
液を使用することを特徴とする非水電解質電池。
A positive electrode comprising a lithium manganese composite oxide, and a negative electrode comprising a carbon material capable of inserting and extracting lithium ions and having a low crystalline carbon material on the particle surface, comprising lithium tetrafluoroborate ( A non-aqueous electrolyte battery using a non-aqueous electrolyte containing LiBF 4 ).
JP10311909A 1998-11-02 1998-11-02 Nonaqueous electrolyte secondary battery Pending JP2000138063A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10311909A JP2000138063A (en) 1998-11-02 1998-11-02 Nonaqueous electrolyte secondary battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10311909A JP2000138063A (en) 1998-11-02 1998-11-02 Nonaqueous electrolyte secondary battery

Publications (1)

Publication Number Publication Date
JP2000138063A true JP2000138063A (en) 2000-05-16

Family

ID=18022887

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10311909A Pending JP2000138063A (en) 1998-11-02 1998-11-02 Nonaqueous electrolyte secondary battery

Country Status (1)

Country Link
JP (1) JP2000138063A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7704640B2 (en) 2005-02-28 2010-04-27 Sanyo Electric Co., Ltd. Non-aqueous electrolyte secondary cell
US7815819B2 (en) * 1999-04-30 2010-10-19 Acep Inc. Electrode materials with high surface conductivity

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7815819B2 (en) * 1999-04-30 2010-10-19 Acep Inc. Electrode materials with high surface conductivity
US8173049B2 (en) 1999-04-30 2012-05-08 Acep Inc. Electrode materials with high surface conductivity
US8257616B2 (en) 1999-04-30 2012-09-04 Acep Inc. Electrode materials with high surface conductivity
US8506852B2 (en) 1999-04-30 2013-08-13 Acep Inc. Electrode materials with high surface conductivity
US8506851B2 (en) 1999-04-30 2013-08-13 Acep Inc. Electrode materials with high surface conductivity
US7704640B2 (en) 2005-02-28 2010-04-27 Sanyo Electric Co., Ltd. Non-aqueous electrolyte secondary cell

Similar Documents

Publication Publication Date Title
US20030044684A1 (en) Positive active material for nonaqueous secondary battery, and nonaqueous secondary battery using the same
JP4961654B2 (en) Nonaqueous electrolyte secondary battery
EP2277230A2 (en) High energy lithium ion secondary batteries
JP2004047180A (en) Nonaqueous electrolytic solution battery
JP2007317534A (en) Non-aqueous electrolyte secondary battery
JP2971403B2 (en) Non-aqueous solvent secondary battery
JP3244389B2 (en) Lithium secondary battery
JP2009212021A (en) Electrode for electrochemical element, nonaqueous secondary battery, and battery system
KR20060052502A (en) Battery
WO2022198651A1 (en) Positive electrode plate, and electrochemical device and electronic device containing positive electrode plate
JP2005251472A (en) Nonaqueous secondary battery and charging method therefor
JP2002237331A (en) Lithium secondary battery
JP2003297354A (en) Lithium secondary battery
JP3650548B2 (en) Electrode active material and non-aqueous electrolyte secondary battery using the electrode active material
JP2001143708A (en) Non-aqueous electrolyte secondary battery
WO2018062202A1 (en) Nonaqueous electrolyte battery and battery pack
JP2002175836A (en) Nonaqueous electrolyte battery
JP2002260726A (en) Nonaqueous electrolyte secondary battery
JP2001357851A (en) Nonaqueous electrolyte secondary battery
JP2001297763A (en) Nonaqueous electrolyte secondary cell
JP4561040B2 (en) Nonaqueous electrolyte secondary battery
JP2000200603A (en) Negative-electrode material, its manufacture, and battery using same
JP2000138063A (en) Nonaqueous electrolyte secondary battery
JP5157253B2 (en) Cathode active material for non-aqueous electrolyte secondary battery and non-aqueous electrolyte secondary battery using the same
JP3322321B2 (en) Cylindrical non-aqueous electrolyte secondary battery