JPH07192724A - Nonaqueous electrolyte secondary battery - Google Patents

Nonaqueous electrolyte secondary battery

Info

Publication number
JPH07192724A
JPH07192724A JP6033434A JP3343494A JPH07192724A JP H07192724 A JPH07192724 A JP H07192724A JP 6033434 A JP6033434 A JP 6033434A JP 3343494 A JP3343494 A JP 3343494A JP H07192724 A JPH07192724 A JP H07192724A
Authority
JP
Japan
Prior art keywords
graphite
carbon material
negative electrode
secondary battery
electrolyte secondary
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.)
Granted
Application number
JP6033434A
Other languages
Japanese (ja)
Other versions
JP3430614B2 (en
Inventor
Tokuo Komaru
篤雄 小丸
Masayuki Nagamine
政幸 永峰
Naoyuki Nakajima
尚幸 中島
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.)
Sony Corp
Original Assignee
Sony Corp
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 Sony Corp filed Critical Sony Corp
Priority to JP03343494A priority Critical patent/JP3430614B2/en
Publication of JPH07192724A publication Critical patent/JPH07192724A/en
Application granted granted Critical
Publication of JP3430614B2 publication Critical patent/JP3430614B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • Y—GENERAL 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Abstract

PURPOSE:To provide a nonaqueous electrolyte secondary battery excellent in energy density, cycle characteristic and reliability by composing a carbon material used as a negative electrode for the nonaqueous electrolyte secondary battery, of a coexistent body including hardly and easily graphitized carbon materials and graphite. CONSTITUTION:A nonaqueous electrolyte secondary battery comprises a negative electrode having a carbon materials capable of doping or dedoping litium as a negative electrode material, a positive electrode having transition metal composite oxide including lithium as a positive electrode active material, and a nonaqueous electrolyte having an electrolyte dissolved in a nonaqueous solvent including carbon ethylene. A coexistent body of non-graphitized carbon material and graphite composed of at least either one of a hardly graphitized carbon material and an easily graphitized carbon material is used as the carbon material for the negative electrode material. Coal or pitch is used as a starting material for the easily graphitized carbon material. A furfuryl alcohol resin or the like is used as a starting material for the hardly graphitized carbon material. The graphite may be either natural graphite or artificial graphite.

Description

【発明の詳細な説明】Detailed Description of the Invention

【０００１】[0001]

【産業上の利用分野】本発明は、炭素材料を負極材料に
用いる非水電解液二次電池に関する。TECHNICAL FIELD The present invention relates to a non-aqueous electrolyte secondary battery using a carbon material as a negative electrode material.

【０００２】[0002]

【従来の技術】近年の電子技術のめざましい進歩は、電
子機器の小型・軽量化を次々と実現させている。それに
伴い、移動用電源としての電池に対しても益々小型・軽
量且つ高エネルギー密度であることが求められるように
なっている。2. Description of the Related Art Recent remarkable advances in electronic technology have made electronic devices smaller and lighter one after another. Along with this, batteries, which are used as mobile power sources, are required to be smaller and lighter and have high energy density.

【０００３】従来、一般用途の二次電池としては鉛電
池、ニッケル・カドミウム電池等の水溶液系二次電池が
主流である。しかし、これらの水溶液系二次電池はサイ
クル特性には優れるものの、電池重量やエネルギー密度
の点で十分に満足できるものとは言えない。Conventionally, an aqueous solution type secondary battery such as a lead battery or a nickel-cadmium battery has been mainly used as a secondary battery for general use. However, although these aqueous secondary batteries have excellent cycle characteristics, they cannot be said to be sufficiently satisfactory in terms of battery weight and energy density.

【０００４】一方、最近、リチウムあるいはリチウム合
金を負極材料として用いる非水電解液二次電池の研究・
開発が盛んに行われている。この非水電解液二次電池は
高エネルギー密度を有し、自己放電も少なく、軽量とい
う優れた特長を有するものである。しかし、この非水電
解液二次電池は、充放電サイクルが進行するのに伴って
充電時に負極上にリチウムがデンドライト状に結晶成長
し、終には正極に到達して内部ショートに至るといった
可能性が高く、実用化が困難であるとされている。On the other hand, recently, research on a non-aqueous electrolyte secondary battery using lithium or a lithium alloy as a negative electrode material
Development is actively done. This non-aqueous electrolyte secondary battery has high energy density, little self-discharge, and is lightweight. However, in this non-aqueous electrolyte secondary battery, lithium can grow into dendrite-like crystals on the negative electrode during charging as the charge / discharge cycle progresses, and eventually reach the positive electrode, causing an internal short circuit. It is said that it is difficult to put into practical use because of its high properties.

【０００５】そこで、さらに、負極材料として炭素材料
を使用した非水電解液二次電池が提案されている。この
非水電解液二次電池は、炭素材料の炭素層間にリチウム
がドープ・脱ドープされることを利用するものであり、
充放電サイクルが進行しても負極上にデンドライト状リ
チウムが析出するといった現象は認められず、高エネル
ギー密度を有し、軽量であるとともに優れた充放電サイ
クル特性を示す。Therefore, a non-aqueous electrolyte secondary battery using a carbon material as a negative electrode material has been proposed. This non-aqueous electrolyte secondary battery utilizes that lithium is doped / dedoped between carbon layers of the carbon material,
Even if the charge / discharge cycle progresses, no phenomenon that dendrite-like lithium is deposited on the negative electrode is observed, and it has a high energy density, is lightweight, and exhibits excellent charge / discharge cycle characteristics.

【０００６】[0006]

【発明が解決しようとする課題】ところで、このような
非水電解液二次電池において、負極材料として使用し得
る炭素材料は各種あるが、初めに負極材料として実用化
された炭素材料はコークスやガラス状炭素等の難黒鉛化
性炭素材料，すなわち有機材料を比較的低温で熱処理す
ることで得られる結晶性の低い炭素材料である。これら
コークスや難黒鉛化性炭素材料で構成された負極と炭酸
プロピレン（ＰＣ）を主溶媒とする電解液を用いた非水
電解液二次電池が既に商品化されている。There are various carbon materials that can be used as the negative electrode material in such a non-aqueous electrolyte secondary battery, but the carbon material first put to practical use as the negative electrode material is coke or It is a non-graphitizable carbon material such as glassy carbon, that is, a carbon material having low crystallinity obtained by heat-treating an organic material at a relatively low temperature. Non-aqueous electrolyte secondary batteries have been already commercialized using a negative electrode composed of these coke or non-graphitizable carbon material and an electrolyte solution containing propylene carbonate (PC) as a main solvent.

【０００７】さらに最近では、結晶構造が発達した高結
晶性炭素材料の黒鉛類が負極材料として用いられるよう
になっている。黒鉛類は、結晶性の低い難黒鉛化性炭素
材料に比べて真密度が高いので、負極材料として使用し
たときに電極充填性が高く、電池を高エネルギー密度に
設計することが可能になる。More recently, graphites, which are highly crystalline carbon materials having a developed crystal structure, have come to be used as negative electrode materials. Since graphites have a higher true density than non-graphitizable carbon materials having low crystallinity, they have a high electrode packing property when used as a negative electrode material, which makes it possible to design a battery with a high energy density.

【０００８】この黒鉛類は、これまで非水溶媒の主溶媒
として汎用されているＰＣを分解するために、負極材料
としての使用は困難であるとされていた。しかし、ＰＣ
の代わりに炭酸エチレン（ＥＣ）を主溶媒として用いる
ことにより、このような不都合が解消されることが判明
し、黒鉛類で構成される負極とＥＣを主溶媒とする電解
液を組み合わせた非水電解液二次電池が提案されてい
る。It has been considered difficult to use this graphite as a negative electrode material because it decomposes PC, which has been widely used as a main solvent of non-aqueous solvents. But the PC
By using ethylene carbonate (EC) as the main solvent instead of, it was found that such inconvenience was solved, and a non-aqueous solution combining a negative electrode composed of graphite and an electrolytic solution containing EC as the main solvent was used. Electrolyte secondary batteries have been proposed.

【０００９】この黒鉛類を負極材料とする非水電解液二
次電池は、高エネルギー密度を有するとともに放電カー
ブが平坦であるため電子機器での電圧変換に際してエネ
ルギーロスがないといった長所も有する。The non-aqueous electrolyte secondary battery using graphite as a negative electrode material has a high energy density and has a flat discharge curve, so that there is no energy loss during voltage conversion in an electronic device.

【００１０】しかしながら、真密度の高い黒鉛類によっ
て構成される負極は、電極充填性が高められる反面、充
放電に際してリチウムイオンの拡散が遅く、分極を生じ
易い。このため、比較的重負荷で充電を行うと、分極に
よって生じる過電圧のために、負極電位がリチウム電位
よりも卑となって表面にリチウム金属が析出し、それが
不動態化してサイクル特性が劣化する。However, the negative electrode composed of graphite having a high true density has a high electrode filling property, but on the other hand, diffusion of lithium ions is slow during charging and discharging, and polarization is likely to occur. For this reason, when the battery is charged under a relatively heavy load, the negative electrode potential becomes less base than the lithium potential and lithium metal is deposited on the surface due to the overvoltage generated by polarization, which is passivated and the cycle characteristics deteriorate. To do.

【００１１】また、実用電池の終止電圧４．２Ｖで定電
圧充電を行った場合、ガラス状炭素で構成される負極を
用いる非水電解液二次電池では、充電終止時に負極単体
の電位が（Ｌｉ極基準で）約５０ｍＶ以下の高さである
のに対して、黒鉛類で構成される負極を用いる非水電解
液二次電池では充電終止時に負極単体の電位が１００〜
１５０ｍＶにまで達する。When constant voltage charging is performed at a final voltage of 4.2 V of a practical battery, in a non-aqueous electrolyte secondary battery using a negative electrode composed of glassy carbon, the potential of the negative electrode alone becomes ( In contrast to the height of about 50 mV or less (based on the Li electrode), in the non-aqueous electrolyte secondary battery using a negative electrode composed of graphite, the potential of the negative electrode alone is 100 to 100 at the end of charging.
It reaches up to 150 mV.

【００１２】このように、同じ終止電圧で充電を行った
にもかかわらず、黒鉛類で構成された負極を用いる非水
電解液二次電池は、ガラス状炭素で構成された負極を用
いる非水電解液二次電池に比べて、充電終止時に負極単
体の電位が５０〜１００ｍＶも高くなる。充電終止時に
負極単体の電位が高いと、正極活物質からリチウムが多
量に引き抜かれて正極の安定性が損なわれ、耐環境性能
において信頼性が乏しいといった問題が生じる。As described above, a non-aqueous electrolyte secondary battery using a negative electrode composed of graphites, even though charged at the same final voltage, is a non-aqueous electrolyte secondary battery using a negative electrode composed of glassy carbon. Compared with the electrolyte secondary battery, the potential of the negative electrode alone becomes higher by 50 to 100 mV at the end of charging. If the electric potential of the negative electrode alone is high at the end of charging, a large amount of lithium is extracted from the positive electrode active material, the stability of the positive electrode is impaired, and there arises a problem that environmental resistance performance is poor in reliability.

【００１３】そこで、本発明は、このような従来の実情
に鑑みて提案されたものであって、高い電極充填性を有
するとともに、充放電に際してリチウムイオンの拡散速
度が速く、さらに充電終止時の負極単体の電位が比較的
卑な負極を有し、エネルギー密度，サイクル特性，信頼
性に優れた非水電解液二次電池を提供することを目的と
する。Therefore, the present invention has been proposed in view of such conventional circumstances, and has a high electrode filling property, a high diffusion rate of lithium ions at the time of charging / discharging, and further at the time of termination of charging. An object of the present invention is to provide a non-aqueous electrolyte secondary battery that has a negative electrode with a relatively negative electric potential as a single negative electrode and is excellent in energy density, cycle characteristics, and reliability.

【００１４】[0014]

【課題を解決するための手段】上述の目的を達成するた
めに、本発明者等が鋭意検討を行った結果、真密度の高
い黒鉛と、黒鉛よりもリチウムイオンの拡散速度が速い
非黒鉛炭素材料を組み合わせて負極に共存させることに
より、高い電極充填性を有するとともに、重負荷充電を
行った場合でもリチウム金属の析出を生ずることがな
く、さらに負極単体の電位が比較的卑であるといった条
件を満たす負極が得られることを見い出すに至った。[Means for Solving the Problems] In order to achieve the above-mentioned object, the inventors of the present invention have conducted extensive studies, and as a result, graphite having a high true density and non-graphite carbon having a higher diffusion rate of lithium ions than graphite By combining materials to coexist in the negative electrode, it has a high electrode filling property, does not cause precipitation of lithium metal even when subjected to heavy load charging, and the potential of the negative electrode alone is relatively base. It has been found that a negative electrode satisfying the above conditions can be obtained.

【００１５】本発明の非水電解液二次電池は、このよう
な知見に基づいて完成されたものであって、負極として
リチウムのドープ・脱ドープが可能な炭素材料を、正極
としてリチウムを含む遷移金属複合酸化物を、さらに非
水電解液を具備してなる非水電解液二次電池において、
負極材料となる炭素材料は、難黒鉛化性炭素材料，易黒
鉛化性炭素材料の少なくともいずれかよりなる非黒鉛炭
素材料と、黒鉛の共存体であることを特徴とするもので
ある。The non-aqueous electrolyte secondary battery of the present invention has been completed based on such findings, and contains a carbon material capable of doping / dedoping lithium as a negative electrode and lithium as a positive electrode. In a non-aqueous electrolyte secondary battery comprising a transition metal composite oxide, further comprising a non-aqueous electrolyte,
The carbon material serving as the negative electrode material is characterized by being a coexisting body of graphite and a non-graphitizable carbon material composed of at least one of a non-graphitizable carbon material and a graphitizable carbon material.

【００１６】また、共存体のうち非黒鉛炭素材料は、断
続充放電法の１サイクル目で測定される１ｇ当たりの放
電容量が、黒鉛材料の断続充放電法の１サイクル目で測
定される１ｇ当たりの放電容量の８０％以上であり、且
つ非黒鉛炭素材料の共存体全体に占める割合が１０〜９
０重量％であることを特徴とするものである。In the non-graphite carbon material among the coexisting substances, the discharge capacity per 1 g measured in the first cycle of the intermittent charging / discharging method is 1 g measured in the first cycle of the intermittent charging / discharging method of the graphite material. 80% or more of the discharge capacity per unit and the proportion of the non-graphite carbon material in the whole coexisting body is 10 to 9
It is characterized by being 0% by weight.

【００１７】さらに、非黒鉛炭素材料は、断続充放電法
の１サイクル目で測定される放電容量において、リチウ
ム電位を基準電位としたときに、０．３Ｖまでの放電容
量の１．５Ｖまでの放電容量に対する比が０．５以上で
あることを特徴とするものである。さらに、共存体のう
ち黒鉛は、真密度が２．１ｇ／ｃｍ3 以上、Ｘ線回折法
で求められる（００２）面の面間隔が０．３４０ｎｍ未
満、（００２）面のＣ軸結晶子厚みが１４．０ｎｍ以上
であることを特徴とするものである。Furthermore, the non-graphite carbon material has a discharge capacity measured in the first cycle of the intermittent charging / discharging method of up to 1.5 V, which is a discharge capacity up to 0.3 V when the lithium potential is used as a reference potential. The ratio to the discharge capacity is 0.5 or more. Further, among coexisting substances, graphite has a true density of 2.1 g / cm 3 or more, a (002) plane spacing of less than 0.340 nm determined by an X-ray diffraction method, and a (002) plane C-axis crystallite thickness. Is 14.0 nm or more.

【００１８】さらに、共存体のうち非黒鉛炭素材料は、
真密度が１．７０ｇ／ｃｍ3 以下、Ｘ線回折法で求めら
れる（００２）面の面間隔が０．３７ｎｍ以上、空気気
流中での示差熱分析において７００℃以上に酸化発熱ピ
ークが観測されない難黒鉛化性炭素であることを特徴と
するものである。Further, among the coexisting substances, the non-graphite carbon material is
True density is 1.70 g / cm 3 or less, the (002) plane spacing determined by X-ray diffraction is 0.37 nm or more, and no oxidation exothermic peak is observed at 700 ° C. or more in differential thermal analysis in an air stream. It is characterized by being non-graphitizable carbon.

【００１９】さらに、難黒鉛化性炭素材料は、リンを含
有することを特徴とするものである。さらに、共存体
は、難黒鉛化性炭素材料，易黒鉛化性炭素材料の少なく
ともいずれかよりなる炭素材料、または難黒鉛化性炭素
材料あるいは易黒鉛化性炭素材料の原料またはそれらの
炭化前駆体に対して、周期率表のＩＶｂ〜ＶＩＩｂ及び
ＶＩＩＩ族元素からなる金属またはその化合物を黒鉛化
触媒として添加し、熱処理されて生成される非黒鉛炭素
材料と黒鉛材料の共存体であることを特徴とするもので
ある。Further, the non-graphitizable carbon material is characterized by containing phosphorus. Further, the coexisting body is a carbon material composed of at least one of a non-graphitizable carbon material and a graphitizable carbon material, or a raw material of a graphitizable carbon material or a graphitizable carbon material, or a carbonization precursor thereof. On the other hand, it is a coexisting body of a non-graphite carbon material and a graphite material produced by adding a metal consisting of an IVb to VIIb or VIII group element of the periodic table or a compound thereof as a graphitization catalyst and heat-treating it. It is what

【００２０】さらに、非水電解液は、炭酸エチレンを含
有する非水溶媒に電解質が溶解されてなる電解液である
ことを特徴とするものである。さらに、非水溶媒は、鎖
状炭酸エステルを含有することを特徴とするものであ
る。さらに、鎖状炭酸エステルが非対称鎖状炭酸エステ
ルであることを特徴とするものである。Further, the non-aqueous electrolytic solution is characterized in that it is an electrolytic solution in which an electrolyte is dissolved in a non-aqueous solvent containing ethylene carbonate. Further, the non-aqueous solvent is characterized by containing a chain carbonic acid ester. Further, the chain carbonic acid ester is an asymmetrical chain carbonic acid ester.

【００２１】さらに、鎖状炭酸エステルがメチルエチル
カーボネートとジメチルカーボネートの混合溶媒である
ことを特徴とするものである。Further, the chain carbonic acid ester is a mixed solvent of methyl ethyl carbonate and dimethyl carbonate.

【００２２】本発明が適用される非水電解液二次電池
は、炭素材料を負極材料とする負極と、リチウムを含む
遷移金属複合酸化物を正極活物質とする正極と、非水電
解液を具備してなるものである。A non-aqueous electrolyte secondary battery to which the present invention is applied includes a negative electrode using a carbon material as a negative electrode material, a positive electrode using a transition metal composite oxide containing lithium as a positive electrode active material, and a non-aqueous electrolyte solution. It is equipped with.

【００２３】本発明では、このような非水電解液二次電
池において、高い電極充填性を有し、且つ重負荷充電に
際してリチウム金属の析出を生ずることがなく、さらに
充電終止時の負極単体の電位が比較的卑であるといった
条件を満たす負極を実現し、エネルギー密度，サイクル
寿命，信頼性の向上を図るために、負極材料として、黒
鉛と、非黒鉛炭素材料の共存体を用いることとする。こ
こで、非黒鉛炭素材料とは、難黒鉛化性炭素材料，易黒
鉛化性炭素材料の単独あるいはこれらの混合物である。According to the present invention, in such a non-aqueous electrolyte secondary battery, it has a high electrode filling property, does not cause deposition of lithium metal during heavy load charging, and further, the negative electrode alone at the end of charging. In order to realize a negative electrode that satisfies the condition that the electric potential is relatively base, and to improve energy density, cycle life, and reliability, we will use a coexisting body of graphite and a non-graphite carbon material as the negative electrode material. . Here, the non-graphitizable carbon material is a non-graphitizable carbon material, an easily graphitizable carbon material, or a mixture thereof.

【００２４】まず、黒鉛は、結晶性が高く真密度の高い
炭素材料である。したがって、この黒鉛によって負極を
構成することにより、負極の電極充填性が高められ、電
池のエネルギー密度が向上する。しかし、黒鉛のみより
なる負極は、充放電に際してリチウムイオンの拡散が遅
く、例えば重負荷充電時に大きく分極してリチウムが表
面に析出し、サイクル特性が劣化する。また、充電後の
負極単体の電位が比較的貴であり、充電時に正極活物質
からリチウムを多量に引き抜き、正極の安定性を損なわ
せる。First, graphite is a carbon material having high crystallinity and high true density. Therefore, by constructing the negative electrode with this graphite, the electrode filling property of the negative electrode is improved and the energy density of the battery is improved. However, in a negative electrode made of only graphite, diffusion of lithium ions is slow during charging / discharging, and for example, during heavy load charging, it is largely polarized and lithium deposits on the surface, degrading cycle characteristics. Further, the potential of the negative electrode after charging is relatively noble, and a large amount of lithium is extracted from the positive electrode active material during charging, which impairs the stability of the positive electrode.

【００２５】これに対して、結晶性の低い非黒鉛炭素材
料は、真密度が低く、電極充填性を得るには不利であ
る。その一方、充放電に際してリチウムイオンの拡散が
速く、重負荷充電を行った場合でも黒鉛を用いる場合の
ようなリチウム金属の析出を生じない。また、充電後の
負極単体の電位も比較的卑であり、正極の安定性を損な
わせることもない。On the other hand, the non-graphite carbon material having a low crystallinity has a low true density and is disadvantageous for obtaining the electrode filling property. On the other hand, lithium ions are rapidly diffused during charge and discharge, and lithium metal deposition does not occur even when heavy load charging is performed as in the case of using graphite. In addition, the electric potential of the negative electrode after charging is relatively base and does not impair the stability of the positive electrode.

【００２６】このような黒鉛と非黒鉛炭素材料は、それ
ぞれ単独で負極を構成すると電池のサイクル寿命が短か
ったり、十分なエネルギー密度が得られない。しかし、
黒鉛と非黒鉛炭素材料を単独で用いずに組み合わせて負
極に共存させると、黒鉛の高真密度性と、非黒鉛炭素材
料のリチウムイオンの高速拡散性の両方を兼ね備えた負
極，すなわち、高い電極充填性を有するとともに、重負
荷充電に際して過電圧状態となった場合にもリチウム金
属が析出することがなく、さらに充電後の負極単体の電
位が比較的卑であり、正極の安定性を損なうことのない
負極が実現することになる。When such a graphite and a non-graphite carbon material respectively constitute the negative electrode, the cycle life of the battery is short and a sufficient energy density cannot be obtained. But,
When graphite and a non-graphite carbon material are not used alone but are combined and coexist in the negative electrode, the negative electrode having both the high true density of graphite and the rapid diffusion of lithium ions of the non-graphite carbon material, that is, a high electrode In addition to having a filling property, lithium metal does not precipitate even when an overvoltage state occurs during heavy load charging, and the potential of the negative electrode alone after charging is relatively base, which may impair the stability of the positive electrode. No negative electrode will be realized.

【００２７】ここで上記黒鉛としては、電極充填性を高
めるために用いられるものであるので、真密度の高いも
のを選択することが望ましく、２．１ｇ／ｃｍ3 以上、
さらに好ましくは２．１８ｇ／ｃｍ3 以上の真密度を有
するものを用いる。Since the above-mentioned graphite is used for enhancing the electrode filling property, it is desirable to select one having a high true density, and 2.1 g / cm 3 or more,
More preferably, a material having a true density of 2.18 g / cm 3 or more is used.

【００２８】上記範囲の真密度を有する黒鉛は、例えば
Ｘ線回折法で求められる（００２）面の面間隔、（００
２）面のＣ軸結晶子厚み、さらにはラマンスペクトルに
おけるＧ値が以下の条件を満足するものである。The graphite having the true density in the above range is, for example, the interplanar spacing of the (002) plane determined by the X-ray diffraction method, and (00
The C-axis crystallite thickness of the 2) plane and the G value in the Raman spectrum satisfy the following conditions.

【００２９】すなわち、（００２）面の面間隔が０．３
４０ｎｍ未満、さらに好ましくは０．３３５ｎｍ以上，
０．３３９ｎｍ以下であり、（００２）面のＣ軸結晶子
厚みが１４．０ｎｍ以上である炭素材料は上記範囲の真
密度を有する。さらに、炭素材料において、上記真密度
条件を満たすためには、ラマンスペクトルにおけるＧ値
が所定の範囲であることが重要である。このラマンスペ
クトルにおけるＧ値は、黒鉛構造に由来するシグナルの
面積強度と、非晶質構造に由来するシグナルの面積強度
の比で表されるものであり、ミクロな結晶構造欠陥の指
標となるものである。このＧ値が２．５以上の炭素材料
は２．１ｇ／ｃｍ3 以上の真密度を有するが、Ｇ値が
２．５未満の炭素材料のうちには２．１ｇ／ｃｍ3以上
の真密度が得られないものがある。That is, the surface spacing of the (002) plane is 0.3.
Less than 40 nm, more preferably 0.335 nm or more,
The carbon material having a thickness of 0.339 nm or less and a C-axis crystallite thickness of the (002) plane of 14.0 nm or more has a true density in the above range. Further, in the carbon material, in order to satisfy the above true density condition, it is important that the G value in the Raman spectrum is within a predetermined range. The G value in this Raman spectrum is represented by the ratio of the area intensity of the signal originating in the graphite structure to the area intensity of the signal originating in the amorphous structure, and is an index of microscopic crystal structure defects. Is. The carbon material having a G value of 2.5 or more has a true density of 2.1 g / cm 3 or more, but the carbon material having a G value of less than 2.5 has a true density of 2.1 g / cm 3 or more. There are things you can't get.

【００３０】本発明において用いる黒鉛としては、結晶
構造パラメータがこれら条件を満たすものが好ましい。
結晶構造パラメータがこれら条件を満たすものであれ
ば、天然黒鉛、または有機材料を炭素化しさらに高温で
熱処理することで得られる人造黒鉛のいずれであっても
良い。The graphite used in the present invention preferably has a crystal structure parameter satisfying these conditions.
As long as the crystal structure parameters satisfy these conditions, either natural graphite or artificial graphite obtained by carbonizing an organic material and further heat-treating it at high temperature may be used.

【００３１】ここで、上記人造黒鉛としては、石炭やピ
ッチを出発原料として生成されるものが代表的である。Here, the artificial graphite is typically produced by using coal or pitch as a starting material.

【００３２】ピッチとしては、コールタール、エチレン
ボトム油、原油等の高温熱分解で得られるタール類、ア
スファルトなどより蒸留（真空蒸留，常圧蒸留，スチー
ム蒸留）、熱重縮合、抽出、化学重縮合等の操作によっ
て得られるものや、その他木材乾留時に生成するピッチ
等が挙げられる。さらにピッチを生成する出発原料とし
ては、ポリ塩化ビニル樹脂、ポリビニルアセテート、ポ
リビニルブチラート、３，５−ジメチルフェノール樹脂
等の高分子化合物を出発原料とするこのも可能である。As pitch, distillation (vacuum distillation, atmospheric distillation, steam distillation), thermal polycondensation, extraction, chemical polycondensation from coal tar, ethylene bottom oil, tars obtained by high temperature thermal decomposition of crude oil, asphalt, etc. Examples thereof include those obtained by operations such as condensation, and other pitches produced during carbonization of wood. Further, as a starting material for producing pitch, a polymer compound such as polyvinyl chloride resin, polyvinyl acetate, polyvinyl butyrate, and 3,5-dimethylphenol resin can be used as a starting material.

【００３３】これら石炭，ピッチ，高分子化合物は、炭
素化の途中最高４００℃程度で液状で存在し、その温度
で保持することで芳香環同士が縮合，多環化して積層配
向した状態となる。その後、５００℃程度以上の温度に
なると、固体の炭素前駆体すなわちセミコークスを形成
する。このような過程は液相炭素化過程と称され、易黒
鉛化性炭素の典型的な生成過程である。These coals, pitches, and polymer compounds exist in a liquid state at a maximum temperature of about 400 ° C. during carbonization, and when kept at that temperature, the aromatic rings are condensed and polycyclic to be in a laminated orientation. . After that, when the temperature reaches about 500 ° C. or higher, a solid carbon precursor, that is, semi-coke is formed. Such a process is called a liquid-phase carbonization process and is a typical formation process of graphitizable carbon.

【００３４】その他、ナフタレン、フェナントレン、ア
ントラセン、トリフェニレン、ピレン、ペリレン、ペン
タフェン、ペンタセン等の縮合多環炭化水素化合物、そ
の他誘導体（例えばこれらのカルボン酸、カルボン酸無
水物、カルボン酸イミド等）、あるいは混合物、アセナ
フチレン、インドール、イソインドール、キノリン、イ
ソキノリン、キノキサリン、フタラジン、カルバゾー
ル、アクリジン、フェナジン、フェナントリジン等の縮
合複素環化合物、さらにはその誘導体も出発原料として
使用可能である。In addition, condensed polycyclic hydrocarbon compounds such as naphthalene, phenanthrene, anthracene, triphenylene, pyrene, perylene, pentaphene and pentacene, other derivatives (for example, carboxylic acid, carboxylic acid anhydride, carboxylic acid imide, etc.) thereof, or Mixtures, condensed heterocyclic compounds such as acenaphthylene, indole, isoindole, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, phenanthridine, and derivatives thereof can also be used as starting materials.

【００３５】以上の有機材料を出発原料として所望の人
造黒鉛を生成するには、例えば上記有機材料を窒素等の
不活性ガス気流中、温度３００〜７００℃で炭化した
後、不活性ガス気流中、昇温速度１〜１００℃／分、到
達温度９００〜１５００℃、保持時間０〜３０時間程度
の条件でか焼し、さらに２０００℃以上、好ましくは２
５００℃以上で熱処理する。勿論、場合によっては炭化
やか焼操作は省略しても良い。In order to produce desired artificial graphite using the above organic materials as starting materials, for example, the above organic materials are carbonized at a temperature of 300 to 700 ° C. in an inert gas stream such as nitrogen and then in an inert gas stream. Calcination under the conditions of a temperature rising rate of 1 to 100 ° C./minute, an ultimate temperature of 900 to 1500 ° C., and a holding time of 0 to 30 hours, and further 2000 ° C. or higher, preferably 2
Heat treatment is performed at 500 ° C. or higher. Of course, in some cases, the carbonization and calcination operations may be omitted.

【００３６】一方、黒鉛とともに負極に共存させる非黒
鉛炭素材料は、難黒鉛化性炭素，易黒鉛化性炭素の単独
あるいはこれらの混合物である。この非黒鉛炭素材料を
選択するに際しては、できるだけイオン拡散性に優れる
ものを選択することが望ましいことは勿論であるが、以
下のような特性も考慮することが好ましい。On the other hand, the non-graphitizable carbon material to be coexisted with the graphite in the negative electrode is a non-graphitizable carbon, an easily graphitizable carbon, or a mixture thereof. When selecting the non-graphite carbon material, it is of course desirable to select a material having as high ion diffusivity as possible, but it is also preferable to consider the following characteristics.

【００３７】まず、第１に、リチウムのドープ・脱ドー
プ量が大きく、それ単体においても負極材料として高い
性能を有するものであることが望ましい。たとえば、断
続充放電法の１サイクル目で測定される１ｇ当たりの放
電容量が同様にして測定される黒鉛材料の放電容量の８
０％以上，好ましくは９０％以上の非黒鉛炭素材料を用
いることが望ましい。First of all, it is desirable that the doping / de-doping amount of lithium is large, and that lithium itself has high performance as a negative electrode material. For example, the discharge capacity per 1 g measured in the first cycle of the intermittent charge / discharge method is 8 times the discharge capacity of the graphite material measured in the same manner.
It is desirable to use 0% or more, preferably 90% or more of a non-graphite carbon material.

【００３８】ここで、断続充放電法とは、特性を調査す
べき炭素試料で試験用電極を作製して電池に組み込み、
充電，放電を途中に休止過程を入れながら断続的に行う
充放電方法である。Here, the intermittent charging / discharging method means that a test electrode is made of a carbon sample whose characteristics are to be investigated, and is incorporated in a battery.
This is a charging / discharging method in which charging / discharging is performed intermittently with a pause process in between.

【００３９】すなわち、断続充放電法を実施するには、
試験用電極へリチウムをドープするために、電池に対し
て、０．５ｍＡの定電流で１時間充電を行った後、２時
間休止するといった充電／休止サイクルを電位変化を観
測しながら繰り返し行う（充電：厳密には、この試験方
法において、炭素材料にリチウムがドープされる過程は
放電であるが、ここでは実電池での実態に合わせて、便
宜上このドーピング過程を充電と称する）。That is, to carry out the intermittent charging / discharging method,
In order to dope the test electrode with lithium, the battery was charged at a constant current of 0.5 mA for 1 hour and then rested for 2 hours, repeating a charge / pause cycle while observing the potential change ( Charging: Strictly speaking, in this test method, the process in which the carbon material is doped with lithium is discharging, but here, for the sake of convenience, this doping process is referred to as charging, in accordance with the actual state of the actual battery).

【００４０】この充電／休止サイクルの繰り返しは、休
止時において電位変化を（時間）-1 /2に対してプロット
することで推定される平衡電位が、３〜１５ｍＶになっ
た時点で終了する。This repetition of the charging / resting cycle ends when the equilibrium potential estimated by plotting the potential change against (time) -1 / 2 during the resting period becomes 3 to 15 mV.

【００４１】次に、試験用電極からリチウムを脱ドープ
するために、電池に対して、０．５ｍＡの定電流で１時
間放電を行った後、２時間休止するといった放電／休止
サイクルを同様に電位変化を観測しながら繰り返し行う
（放電：厳密には、この試験方法において、炭素材料か
らリチウムが脱ドープされる過程は充電であるが、この
場合も実電池での実態に合わせて、便宜上この脱ドープ
過程を放電と称する）。Next, in order to dedope lithium from the test electrode, the battery was discharged at a constant current of 0.5 mA for 1 hour and then rested for 2 hours. Repeatedly observing the potential change (discharge: Strictly speaking, in this test method, the process of dedoping lithium from the carbon material is charging, but in this case as well, this process is convenient for the actual battery. The dedoping process is called discharge).

【００４２】この放電／休止サイクルの繰り返しは、端
子電圧が１．５Ｖになった時点で終了する。This discharge / pause cycle is repeated when the terminal voltage reaches 1.5V.

【００４３】このような放電，充電によって得られた時
間対電位の充放電カーブから、炭素材料１ｇ当たりの放
電容量が求められることになる。The discharge capacity per 1 g of the carbon material can be obtained from the charge / discharge curve of time vs. potential obtained by such discharge and charge.

【００４４】このようにして断続充放電法を１サイクル
行い、そのときに求められる１ｇ当たりの放電容量が、
同様にして求められる黒鉛材料の１ｇ当たりの放電容量
の８０％以上，好ましくは９０％以上の非黒鉛炭素材料
は、黒鉛で得られる高容量を損なわせることなく、電池
のエネルギー密度の向上に貢献する。なお、黒鉛の断続
充放電法の１サイクル目で求められる１ｇ当たりの放電
容量は２７０ｍＡｈ以上であることが望ましい。In this way, the intermittent charging / discharging method is performed for one cycle, and the discharge capacity per 1 g obtained at that time is
A non-graphite carbon material having a discharge capacity per gram of the graphite material of 80% or more, preferably 90% or more, which is similarly obtained, contributes to the improvement of the energy density of the battery without impairing the high capacity obtained by graphite. To do. It is desirable that the discharge capacity per 1 g of graphite, which is obtained in the first cycle of the intermittent charging / discharging method, is 270 mAh or more.

【００４５】また、非黒鉛炭素材料としては、第２に、
組み合わせて用いられる黒鉛が充電後の単極開回路電位
がリチウム基準で貴であり、正極から引き抜くリチウム
が多く、正極の安定性を損ねるので、このような黒鉛の
特性を緩和すべく、充放電カーブのリチウム電位近傍に
平坦部分を比較的長く有するものが望ましい。As the non-graphite carbon material, secondly,
The graphite used in combination has a single-pole open circuit potential after charging that is noble on the basis of lithium, and a large amount of lithium is extracted from the positive electrode, impairing the stability of the positive electrode. A curve having a relatively long flat portion near the lithium potential is desirable.

【００４６】具体的には、上記断続充放電法の１サイク
ル目で測定される放電容量において、リチウム電位を基
準としたときに、０．３Ｖまでの放電容量の１．５Ｖま
での放電容量に対する比が０．５以上の、非黒鉛炭素材
料を用いることが望ましい。このような非黒鉛炭素材料
を用いることにより、正極が安定化し、電池の耐環境性
能が向上する。Specifically, in the discharge capacity measured in the first cycle of the above intermittent charging / discharging method, the discharge capacity up to 0.3 V with respect to the discharge capacity up to 1.5 V is referenced to the lithium potential. It is desirable to use a non-graphite carbon material with a ratio of 0.5 or more. By using such a non-graphite carbon material, the positive electrode is stabilized and the environmental resistance performance of the battery is improved.

【００４７】この他、黒鉛はリチウムがドープされたと
きに炭素層間が伸長して電極全体を膨張させ、これによ
りセパレータを圧迫して内部短絡を誘発する可能性があ
るので、これと組み合わせる非黒鉛炭素材料には、リチ
ウムドープ時の電極の寸法変化が少ないことも、非黒鉛
炭素材料の具備すべき第３の条件として挙げられる。In addition, when graphite is doped with lithium, the carbon layers may expand to expand the entire electrode, thereby compressing the separator and inducing an internal short circuit. The fact that the dimensional change of the electrode when the lithium is doped in the carbon material is small is also mentioned as the third condition that the non-graphite carbon material should have.

【００４８】これら条件を満足する非黒鉛炭素材料とし
ては、次に例示する出発原料を焼成して得られる易黒鉛
化性炭素材料がある。As a non-graphite carbon material satisfying these conditions, there is a graphitizable carbon material obtained by firing the starting materials shown below.

【００４９】すなわち、易黒鉛化性炭素材料を生成する
出発原料としては、石炭やピッチが代表的である。That is, coal and pitch are typical starting materials for producing the graphitizable carbon material.

【００５０】ピッチとしては、コールタール、エチレン
ボトム油、原油等の高温熱分解で得られるタール類、ア
スファルトなどより蒸留（真空蒸留、常圧蒸留、スチー
ム蒸留）、熱重縮合、抽出、化学重縮合等の操作によっ
て得られるものや、木材乾留時に生成するものなどが挙
げられる。As pitch, distillation (vacuum distillation, atmospheric distillation, steam distillation), thermal polycondensation, extraction, chemical polycondensation from coal tar, ethylene bottom oil, tars obtained by high-temperature thermal decomposition of crude oil, asphalt, etc. Examples thereof include those obtained by operations such as condensation and those produced during carbonization of wood.

【００５１】ポリ塩化ビニル樹脂、ポリビニルアセテー
ト、ポリビニルブチラート、３，５−ジメチルフェノー
ル樹脂等の高分子化合物を出発原料とすることも可能で
ある。Polymeric compounds such as polyvinyl chloride resin, polyvinyl acetate, polyvinyl butyrate, and 3,5-dimethylphenol resin can also be used as starting materials.

【００５２】その他、ナフタレン、フェナントレン、ア
ントラセン、トリフェニレン、ピレン、ペリレン、ペン
タフェン、ペンタセン等の縮合多環炭化水素化合物、そ
の他誘導体（例えばこれらのカルボン酸、カルボン酸無
水物、カルボン酸イミド等）、あるいは混合物、アセナ
フチレン、インドール、イソインドール、キノリン、イ
ソキノリン、キノキサリン、フタラジン、カルバゾー
ル、アクリジン、フェナジン、フェナントリジン等の縮
合複素環化合物、さらにはその誘導体も原料として使用
可能である。In addition, condensed polycyclic hydrocarbon compounds such as naphthalene, phenanthrene, anthracene, triphenylene, pyrene, perylene, pentaphene and pentacene, other derivatives (for example, carboxylic acid, carboxylic acid anhydride, carboxylic acid imide, etc.) thereof, or Mixtures, condensed heterocyclic compounds such as acenaphthylene, indole, isoindole, quinoline, isoquinoline, quinoxaline, phthalazine, carbazole, acridine, phenazine, phenanthridine, and their derivatives can also be used as raw materials.

【００５３】易黒鉛化性炭素材料は、以上の出発原料
を、例えば、窒素等の不活性ガス気流中にて３００〜７
００℃で炭化した後、１〜１００℃／分の速度で９００
〜１５００℃まで昇温して、到達温度にて０〜３０時間
保持することによって得られる。勿論、場合によっては
炭化操作を省略しても良い。The easily graphitizable carbon material is prepared by using the above starting materials in an amount of 300 to 7 in a stream of an inert gas such as nitrogen.
After carbonizing at 00 ° C, 900 at a rate of 1-100 ° C / min
It is obtained by raising the temperature to ˜1500 ° C. and holding at the ultimate temperature for 0 to 30 hours. Of course, in some cases, the carbonization operation may be omitted.

【００５４】また、さらに上記要件を満たす非黒鉛炭素
材料としては、次に例示する出発原料を焼成することで
得られる難黒鉛化性炭素材料が挙げられる。Further, examples of the non-graphite carbon material which further satisfies the above requirements include non-graphitizable carbon materials obtained by firing the starting materials exemplified below.

【００５５】難黒鉛化炭素材料を生成する出発原料とし
ては、フルフリルアルコール樹脂、フルフラール樹脂、
フラン樹脂、フェノール樹脂、アクリル樹脂、ハロゲン
化ビニル樹脂、ポリイミド樹脂、ポリアミドイミド樹
脂、ポリアミド樹脂、ポリアセチレン、ポリ（Ｐ−フェ
ニレン）等の共役系樹脂、セルロースおよびその誘導体
等の有機高分子系化合物を使用することが出来る。As a starting material for producing the non-graphitizable carbon material, furfuryl alcohol resin, furfural resin,
Furan resin, phenol resin, acrylic resin, vinyl halide resin, polyimide resin, polyamideimide resin, polyamide resin, polyacetylene, conjugated resin such as poly (P-phenylene), and organic polymer compounds such as cellulose and its derivatives Can be used.

【００５６】また、特定のＨ／Ｃ原子比を有する石油ピ
ッチに酸素を含む官能基を導入（いわゆる酸素架橋）し
たものも、炭素化の過程（４００℃以上）で溶融するこ
となく、固相炭素化して難黒鉛化性炭素材料となる。In addition, a product obtained by introducing a functional group containing oxygen (so-called oxygen bridge) into petroleum pitch having a specific H / C atomic ratio does not melt in the process of carbonization (400 ° C. or higher) and is solid phase. Carbonized to become a non-graphitizable carbon material.

【００５７】前記石油ピッチは、コールタール、エチレ
ンボトム油、原油等の高温熱分解で得られるタール類、
アスファルトなどより蒸留（真空蒸留、常圧蒸留、スチ
ーム蒸留）、熱重縮合、抽出、化学重縮合等の操作によ
って得られる。難黒鉛化性炭素材料を得るためには、石
油ピッチのＨ／Ｃ原子比が重要で、０．６〜０．８とす
る必要がある。The petroleum pitch is tars obtained by high temperature pyrolysis of coal tar, ethylene bottom oil, crude oil, etc.,
It is obtained from asphalt and the like by operations such as distillation (vacuum distillation, atmospheric distillation, steam distillation), thermal polycondensation, extraction, chemical polycondensation and the like. In order to obtain a non-graphitizable carbon material, the H / C atomic ratio of petroleum pitch is important and needs to be 0.6 to 0.8.

【００５８】酸素を含む官能基を導入する方法は限定さ
れないが、例えば、硝酸、混酸、硫酸、次亜塩素等の水
溶液による湿式法、空気や酸素等の酸化性ガスによる乾
式法あるいは、硫黄、硝酸アンモニア、過硫酸アンモニ
ア、塩化第二鉄等の固体試薬による反応が用いられる。
酸素含有率は特に限定されないが、特開平３−２５２０
５３号公報に示すように、好ましくは３％以上、さらに
好ましくは５％以上である。この酸素含有率は、最終的
に製造される炭素材料の結晶構造に影響を与える。The method of introducing the functional group containing oxygen is not limited, but for example, a wet method using an aqueous solution of nitric acid, mixed acid, sulfuric acid, hypochlorous acid, a dry method using an oxidizing gas such as air or oxygen, or sulfur, A reaction with a solid reagent such as ammonium nitrate, ammonium persulfate, and ferric chloride is used.
The oxygen content is not particularly limited, but it is disclosed in JP-A-3-2520.
As shown in Japanese Patent No. 53, the content is preferably 3% or more, more preferably 5% or more. This oxygen content affects the crystal structure of the finally produced carbon material.

【００５９】難黒鉛化性炭素材料は、以上の出発原料
を、例えば、窒素等の不活性ガス気流中にて３００〜７
００℃で炭化した後、１〜１００℃／分の速度で９００
〜１５００℃まで昇温して、到達温度にて０〜３０時間
保持することによって得られる。勿論、場合によっては
炭化操作を省略しても良い。For the non-graphitizable carbon material, the above-mentioned starting materials are, for example, 300 to 7 in a stream of an inert gas such as nitrogen.
After carbonizing at 00 ° C, 900 at a rate of 1-100 ° C / min
It is obtained by raising the temperature to ˜1500 ° C. and holding at the ultimate temperature for 0 to 30 hours. Of course, in some cases, the carbonization operation may be omitted.

【００６０】このようにして得られる難黒鉛化性炭素材
料の中で、特にフルフリルアルコールあるいはフルフラ
ールのホモポリマー、コポリマーよりなるフラン樹脂
や、特定のＨ／Ｃ原子比を有する石油ピッチを酸素架橋
した出発原料を用いたものは、００２面の面間隔が０．
３７ｎｍ以上、真密度１．７０ｇ／ｃｍ3 以下、かつＤ
ＴＡで７００℃以上に酸化発熱ピークを持たず、充放電
可能な容量も大きく、電池の負極材料として非常に良好
な特性を示す。Among the non-graphitizable carbon materials thus obtained, furan resin composed of furfuryl alcohol or furfural homopolymer or copolymer, or petroleum pitch having a specific H / C atomic ratio is oxygen-crosslinked. In the case of using the starting material described above, the 002 plane spacing is 0.
37 nm or more, true density 1.70 g / cm 3 or less, and D
TA does not have an oxidation exothermic peak at 700 ° C. or higher, has a large chargeable / dischargeable capacity, and exhibits very good characteristics as a negative electrode material of a battery.

【００６１】また、特願平１−１９７５９６号公報に記
載されるリン、酸素、炭素を主成分とする化合物も前記
難黒鉛化性炭素材料と同様の物性パラメータを示し、負
極材料として好適である。Further, the compound containing phosphorus, oxygen and carbon as the main components described in Japanese Patent Application No. 1-197596 shows the same physical property parameters as the non-graphitizable carbon material, and is suitable as a negative electrode material. .

【００６２】さらに、上記出発原料を、焼成時に発生す
る種々の揮発成分が効率良く除去される雰囲気で焼成し
て得られた難黒鉛化性炭素材料も、リチウムドープ能力
が大きく、好ましい。Further, a non-graphitizable carbon material obtained by firing the above-mentioned starting material in an atmosphere in which various volatile components generated during firing are efficiently removed is also preferable because of its large lithium doping ability.

【００６３】有機材料の焼成中に発生する揮発成分は、
例えば雰囲気を不活性ガスフロー雰囲気とすることによ
り効率良く除去される。このとき不活性ガスは原料１ｇ
当たり０．１ｍｌ／分以上の流量でフローさせることが
好ましい。さらに焼成を真空排気下で行うと、より効率
良く揮発成分が除去され、リチウムドープ能力の大きな
難黒鉛化性炭素材料が得られる。Volatile components generated during firing of the organic material are
For example, the atmosphere can be efficiently removed by using an inert gas flow atmosphere. At this time, the inert gas is 1 g of raw material
It is preferable to flow at a flow rate of 0.1 ml / min or more. Further, if the firing is performed under vacuum exhaust, the volatile components are removed more efficiently, and a non-graphitizable carbon material having a large lithium doping ability is obtained.

【００６４】本発明では、以上に例示した難黒鉛化性炭
素あるいは易黒鉛化性炭素の単独あるいはこれらの混合
物の非黒鉛炭素材料と、黒鉛の共存体を負極材料として
使用する。In the present invention, the non-graphitizable carbon material of the non-graphitizable carbon or the easily graphitizable carbon exemplified above or a mixture thereof is used as a negative electrode material.

【００６５】ここで、共存体の全体に対する非黒鉛炭素
材料の割合は、電極充填密度，体積当たりの充放電能
力，リチウムイオンの拡散速度，電池重量の観点から１
０〜９０％，好ましくは２０〜８０％とすることが望ま
しい。また、この範囲では、黒鉛の混合比率を大きくす
ると電極充填密度が大きくなる。一方、難黒鉛化性炭素
の混合比率を大きくすると充放電に際するリチウムイオ
ンの拡散速度が向上し、過電圧時のリチウムの析出を防
止する上で有利となるとともに負極重量が軽量化する。
したがって、それぞれの割合は、どの特性を重要視する
必要があるかで適宜選択することが好ましい。Here, the ratio of the non-graphite carbon material to the entire coexisting material is 1 from the viewpoint of the electrode packing density, the charge / discharge capacity per volume, the diffusion rate of lithium ions, and the battery weight.
It is desired to be 0 to 90%, preferably 20 to 80%. In this range, the electrode packing density increases as the mixing ratio of graphite increases. On the other hand, if the mixing ratio of the non-graphitizable carbon is increased, the diffusion rate of lithium ions at the time of charging / discharging is improved, which is advantageous in preventing the precipitation of lithium during overvoltage and the weight of the negative electrode is reduced.
Therefore, it is preferable to appropriately select the respective ratios depending on which characteristics need to be emphasized.

【００６６】これら黒鉛と非黒鉛炭素材料の共存体は、
以下のようにして調製できる。まず、別々に焼成された
黒鉛，非黒鉛炭素材料をそれぞれ粉砕，分級して粉末状
とした後、互いに混ぜ合わせ、この混合炭素粉末を共存
体として負極に供する方法がある。あるいは、原料段階
で、黒鉛と非黒鉛炭素材料の出発原料とを混合しておく
ことで黒鉛と非黒鉛炭素材料の複合炭素材料を生成し、
この複合炭素材料を粉砕，分級したものを共存体として
負極に供するようにしても良い。この場合、非黒鉛炭素
材料の収率を、予め求めておき、非黒鉛炭素材料の出発
原料はこの収率に基づいた混合率で混合する。The coexisting body of these graphite and non-graphite carbon materials is
It can be prepared as follows. First, there is a method in which separately fired graphite and non-graphite carbon materials are crushed and classified to form powder, and then mixed with each other, and the mixed carbon powder is used as a coexisting body for the negative electrode. Alternatively, at the raw material stage, a composite carbon material of graphite and a non-graphite carbon material is produced by mixing graphite and a starting material of a non-graphite carbon material,
The composite carbon material may be crushed and classified and provided as a coexisting body for the negative electrode. In this case, the yield of the non-graphite carbon material is obtained in advance, and the starting materials of the non-graphite carbon material are mixed at a mixing rate based on this yield.

【００６７】また、以下のような手法によっても共存体
を得ることは可能である。すなわち、非黒鉛炭素材料の
原料有機材料、焼成前の炭化前駆体、及び焼成後の炭素
材料自身に、黒鉛化触媒を加え熱処理することで非黒鉛
炭素材料中に黒鉛相を生成させ、共存体を得る方法であ
る。一般に、鉄やニッケルに代表されるＩＶｂ〜ＶＩＩ
ｂ及びＶＩＩＩ族元素が黒鉛化触媒作用を持つと言われ
ている。これらの金属あるいは金属元素を含む無機化合
物及び有機金属錯体等有機化合物を加えて加熱処理する
ことで、比較的低温で黒鉛相を生成させることができ
る。It is also possible to obtain a coexisting substance by the following method. That is, by adding a graphitization catalyst to the raw material organic material of the non-graphite carbon material, the carbonization precursor before firing, and the carbon material itself after firing, a graphite phase is generated in the non-graphite carbon material to form a coexisting substance. Is a way to get. Generally, IVb to VII represented by iron and nickel
It is said that elements b and VIII have a graphitization catalytic action. By adding an inorganic compound containing these metals or metal elements and an organic compound such as an organic metal complex and performing heat treatment, a graphite phase can be generated at a relatively low temperature.

【００６８】添加する触媒は、その形態により、粉体か
ら溶解された溶液等まで様々な形で添加することができ
る。触媒の添加量としては、添加される炭素材料の様々
な状態，即ち、原料有機材料、焼成前の炭化前駆体、焼
成後の炭素材料に対し、重量比で０．１〜５０％の範囲
にすることが好ましい。例えば、原料有機材料への添加
を考えた場合には、熱処理を経るに従い、揮発する有機
成分とともに触媒が系外に散逸してしまうため、触媒添
加量を大きくする必要がある。The catalyst to be added can be added in various forms such as powder to dissolved solution depending on its form. The amount of the catalyst added is in the range of 0.1 to 50% by weight with respect to various states of the carbon material to be added, that is, the raw material organic material, the carbonization precursor before firing, and the carbon material after firing. Preferably. For example, when the addition to the raw material organic material is considered, it is necessary to increase the addition amount of the catalyst because the catalyst is scattered out of the system along with the volatile organic components as the heat treatment is performed.

【００６９】最終的な熱処理の温度や保持時間等の条件
により、共存体内の黒鉛相の結晶性をコントロールする
ことが可能であるが、その温度は、触媒の添加量及び添
加される炭素材料の状態により適宜に選択される。前記
のごとく触媒黒鉛化により得られた共存体においては、
Ｘ線回折法により求められる回折ピークを幾何学的処理
によって非黒鉛炭素材料と黒鉛ピークに分離し、その割
合を計算することにより混合比率を求めることができ
る。The crystallinity of the graphite phase in the coexisting body can be controlled by the conditions such as the temperature and the holding time of the final heat treatment. The temperature depends on the addition amount of the catalyst and the carbon material to be added. It is appropriately selected depending on the state. In the coexistent obtained by catalytic graphitization as described above,
The mixing ratio can be determined by separating the diffraction peak obtained by the X-ray diffraction method into a non-graphite carbon material and the graphite peak by geometrical treatment and calculating the ratio.

【００７０】なお、以上のような共存体において、粉砕
処理は、炭素材料生成過程中の炭化、か焼、高温熱処理
の前後あるいは昇温過程の間のいずれで行っても構わな
い。In the coexisting body as described above, the pulverization treatment may be carried out before or after carbonization, calcination, high temperature heat treatment during the carbon material forming process, or during the temperature raising process.

【００７１】負極に供する炭素材料としては、粒子径が
１μｍ以上のものを用いることが好ましい。負極材料中
に粒径１μｍ未満の炭素材料粒子が多量に含有されてい
ると、充放電サイクル初期において充電しても放電でき
ない不可逆な容量が増大する。この理由は定かではない
が、１μｍ以下の粒子は、比表面積が大きいため、電解
液との反応面積が広く副反応を起こし易いからと考えら
れる。The carbon material used for the negative electrode preferably has a particle size of 1 μm or more. When a large amount of carbon material particles having a particle size of less than 1 μm are contained in the negative electrode material, the irreversible capacity that cannot be discharged even when charged in the initial charge / discharge cycle increases. The reason for this is not clear, but it is considered that particles having a particle size of 1 μm or less have a large specific surface area and thus have a large reaction area with the electrolytic solution and easily cause a side reaction.

【００７２】これら炭素粉末の粒子径の上限について
は、適用する電池の大きさや構造によって異なり、少な
くともセパレータの厚みを越えない範囲に設定すること
が好ましい。したがって、円筒型電池の場合、電極は薄
い電極とセパレータとを交互に積層巻回してなる渦巻構
造とされ、このセパレータの厚さはできるだけ薄いほう
が好ましいので、粒子径の上限は比較的小粒径範囲に設
定される。また大型の電池であれば、炭素粉末の粒子径
を大粒径範囲に設定できる。The upper limit of the particle diameter of these carbon powders depends on the size and structure of the battery to which they are applied, and it is preferable to set at least a range not exceeding the thickness of the separator. Therefore, in the case of a cylindrical battery, the electrode has a spiral structure in which thin electrodes and separators are alternately laminated and wound, and it is preferable that the thickness of this separator is as thin as possible. Therefore, the upper limit of the particle size is relatively small. Set to range. In the case of a large battery, the particle size of carbon powder can be set in a large particle size range.

【００７３】一方、正極を構成する正極活物質として
は、負極の容量能を最大限に発揮させるために、定常状
態（例えば５回程度充放電を繰り返した後）で、負極に
対して炭素材料１ｇ当たり２５０ｍＡｈ以上の充放電容
量相当分のＬｉを供給できることが必要であり、３００
ｍＡｈ以上、より好ましくは３３０ｍＡｈ以上の充放電
容量相当分のＬｉを供給し得る遷移金属化合物であるこ
とがより好ましい。On the other hand, as the positive electrode active material constituting the positive electrode, in order to maximize the capacity of the negative electrode, a carbon material is used for the negative electrode in a steady state (for example, after repeating charging and discharging about 5 times). It is necessary to supply Li corresponding to a charge / discharge capacity of 250 mAh or more per 1 g, and 300
It is more preferable that the transition metal compound is capable of supplying Li corresponding to the charge / discharge capacity of not less than mAh, more preferably not less than 330 mAh.

【００７４】なお、Ｌｉはかならずしも正極活物質から
全て供給される必要はなく、要は電池系内に炭素材料１
ｇ当たり２５０ｍＡｈ以上の充放電容量相当分のＬｉが
存在すれば良い。このＬｉの量は、電池の放電容量を測
定することによって判断することとする。It is not always necessary that Li is entirely supplied from the positive electrode active material.
It suffices that Li corresponding to a charge / discharge capacity of 250 mAh or more exists per g. The amount of Li will be determined by measuring the discharge capacity of the battery.

【００７５】以上のようなイオン供給能力を有する遷移
金属化合物としては、例えば一般式ＬｉＭＯ2 （ただし
ＭはＣｏ，Ｎｉの少なくとも１種を表す。）で表される
リチウム遷移金属複合酸化物やＬｉを含んだ層間化合物
等が好適である。Examples of the transition metal compound having the above-mentioned ion supplying ability include a lithium transition metal composite oxide represented by the general formula LiMO 2 (where M represents at least one of Co and Ni) and Li. An intercalation compound or the like containing is preferable.

【００７６】本発明の非水電解液二次電池において、非
水電解液としては、非水溶媒に電解質を混合してなるも
のが用いられる。In the non-aqueous electrolyte secondary battery of the present invention, a non-aqueous electrolyte prepared by mixing an electrolyte with a non-aqueous solvent is used.

【００７７】ここで、非水溶媒としては、負極を構成す
る黒鉛によって分解し難いことからＥＣを主溶媒に用い
ることが前提となる。そして、さらにこのＥＣに複数の
溶媒を添加し、導電率を向上させて電流特性を改善す
る，電解液の凝固点を低下させて低温特性を改善する，
さらに、リチウム金属との反応性を低下させて安全性を
改善することが望ましい。As the non-aqueous solvent, it is premised that EC is used as the main solvent because it is difficult to decompose by the graphite constituting the negative electrode. Then, a plurality of solvents are further added to this EC to improve the electric conductivity to improve the current characteristics, and to lower the freezing point of the electrolytic solution to improve the low temperature characteristics.
Furthermore, it is desirable to reduce the reactivity with lithium metal to improve safety.

【００７８】まず、このような第２の成分溶媒として
は、鎖状炭酸エステルを添加することが好ましい。特に
鎖状炭酸エステルのうちメチルエチルカーボネート（Ｍ
ＥＣ），メチルプロピルカーボネート（ＭＰＣ）等の非
対称鎖状炭酸エステル、ＭＥＣとＤＭＣの混合溶媒が上
記第２の成分溶媒として好適である。なお、第２の成分
溶媒となるＭＥＣとＤＭＣの混合溶媒において、ＭＥ
Ｃ：ＤＭＣ（体積比率）は２：８〜９：１の範囲に設定
することが好ましい。また、主成分溶媒となるＥＣと第
２の成分溶媒を混合するに際しては、ＥＣ：第２成分溶
媒（体積比率）は７：３〜３：７の範囲に設定すること
が好ましい。First, it is preferable to add a chain ester carbonate as the second component solvent. Methyl ethyl carbonate (M
EC), an asymmetric chain ester carbonate such as methylpropyl carbonate (MPC), and a mixed solvent of MEC and DMC are suitable as the second component solvent. In the mixed solvent of MEC and DMC which is the second component solvent,
C: DMC (volume ratio) is preferably set in the range of 2: 8 to 9: 1. Further, when mixing the EC as the main component solvent and the second component solvent, it is preferable to set the EC: second component solvent (volume ratio) in the range of 7: 3 to 3: 7.

【００７９】電解液はこのような非水溶媒に電解質が添
加されて構成されるが、電解質としてはこの種の電池に
用いられるものであればいずれも使用可能である。例え
ば、ＬｉＰＦ6 ，ＬｉＣｌＯ4 ，ＬｉＡｓＦ6 ，ＬｉＢ
Ｆ4 ，ＬｉＢ（Ｃ6 Ｈ5 ）4，ＣＨ3 ＳＯ3 Ｌｉ，ＣＦ
3 ＳＯ3 Ｌｉ，ＬｉＣｌ，ＬｉＢｒ等が挙げられ、中で
もＬｉＰＦ6 が好適である。The electrolytic solution is formed by adding an electrolyte to such a non-aqueous solvent, and any electrolyte can be used as long as it is used in this type of battery. For example, LiPF 6 , LiClO 4 , LiAsF 6 , LiB
F 4 , LiB (C 6 H 5 ) 4 , CH 3 SO 3 Li, CF
3 SO 3 Li, LiCl, LiBr and the like can be mentioned, of which LiPF 6 is preferable.

【００８０】[0080]

【作用】本発明の非水電解液二次電池では、黒鉛あるい
は非黒鉛炭素材料を単独で用いずに、黒鉛と非黒鉛炭素
材料の共存体を負極材料として使用する。In the non-aqueous electrolyte secondary battery of the present invention, graphite or a non-graphite carbon material is not used alone, but a coexisting body of graphite and a non-graphite carbon material is used as a negative electrode material.

【００８１】黒鉛は、結晶性が高く真密度の高い炭素材
料である。したがって、この黒鉛によって負極を構成す
ることにより、負極の電極充填性が高められ、電池のエ
ネルギー密度が向上する。しかし、黒鉛のみよりなる負
極は、充放電に際してリチウムイオンの拡散が遅い。こ
のため、重負荷充電を行うと、大きく分極し、その過電
圧のために負極電位がリチウム電位よりも卑となってリ
チウム金属が表面に析出し、サイクル特性が劣化する。
また、充電後の負極単体の電位が比較的貴であり、充電
時に正極活物質からリチウムを多量に引き抜き、正極の
安定性を損なわせる。Graphite is a carbon material having high crystallinity and high true density. Therefore, by constructing the negative electrode with this graphite, the electrode filling property of the negative electrode is improved and the energy density of the battery is improved. However, a negative electrode made of only graphite has a slow diffusion of lithium ions during charge and discharge. For this reason, when heavy load charging is performed, it is largely polarized, and the negative electrode potential becomes baser than the lithium potential due to the overvoltage, and lithium metal is deposited on the surface, and the cycle characteristics deteriorate.
Further, the potential of the negative electrode after charging is relatively noble, and a large amount of lithium is extracted from the positive electrode active material during charging, which impairs the stability of the positive electrode.

【００８２】これに対して、結晶性の低い非黒鉛炭素材
料は、真密度が低く、電極充填性を得るには不利であ
る。その一方、充放電に際してリチウムイオンの拡散が
速く、重負荷充電を行った場合でも黒鉛のみより構成さ
れる負極のようなリチウム金属の析出を生じない。ま
た、充電後の負極単体の電位も比較的卑であり、正極の
安定性を損なうこともない。On the other hand, the non-graphite carbon material having a low crystallinity has a low true density and is disadvantageous in obtaining the electrode filling property. On the other hand, lithium ions are rapidly diffused during charge and discharge, and even when subjected to heavy load charging, precipitation of lithium metal unlike a negative electrode composed of graphite alone does not occur. In addition, the electric potential of the negative electrode after charging is relatively base and does not impair the stability of the positive electrode.

【００８３】このような黒鉛と非黒鉛炭素材料をそれぞ
れ単独で負極を構成すると電池のサイクル寿命が短かっ
たり、十分なエネルギー密度が得られない。しかし、黒
鉛と非黒鉛炭素材料を組み合わせて負極材料に用いる
と、黒鉛の高真密度性，難黒鉛化性炭素のリチウムイオ
ンの高速拡散性の両方を兼ね備えた負極，すなわち、高
い電極充填性を有するとともに、重負荷充電に際して過
電圧状態となった場合でもリチウム金属が析出すること
がなく、さらに充電後の負極単体の電位が卑であり、正
極の安定性を損なわせることのない負極が実現すること
になる。If such a graphite and a non-graphite carbon material are individually used to form the negative electrode, the cycle life of the battery is short and a sufficient energy density cannot be obtained. However, when graphite and a non-graphite carbon material are combined and used as a negative electrode material, a negative electrode having both a high true density of graphite and a high-speed diffusion of lithium ions of non-graphitizable carbon, that is, a high electrode packing property is obtained. In addition to that, even if an overvoltage state occurs during heavy load charging, lithium metal does not deposit, and the potential of the negative electrode after charging is base, and a negative electrode that does not impair the stability of the positive electrode is realized. It will be.

【００８４】なお、黒鉛としては、真密度が２．１ｇ／
ｃｍ3 以上、Ｘ線回折法で求められる（００２）面の面
間隔が０．３４０ｎｍ未満、（００２）面のＣ軸結晶子
厚みが１４．０ｎｍ以上、ラマンスペクトルにおけるＧ
値が２．５以上なる条件を満たすものを用いのが好まし
い。このような結晶構造パラメータを有する黒鉛は特に
電極充填性が高いので、さらにエネルギー密度が向上す
る。The true density of graphite is 2.1 g /
cm 3 or more, the interplanar spacing of the (002) plane determined by X-ray diffraction is less than 0.340 nm, the C-axis crystallite thickness of the (002) plane is 14.0 nm or more, G in the Raman spectrum
It is preferable to use one that satisfies the condition that the value is 2.5 or more. Since graphite having such a crystal structure parameter has a particularly high electrode packing property, the energy density is further improved.

【００８５】また、非黒鉛炭素材料としては、真密度が
１．７０ｇ／ｃｍ3 以下、Ｘ線回折法で求められる（０
０２）面の面間隔が０．３７ｎｍ以上、空気気流中での
示差熱分析において７００℃以上に酸化発熱ピークが観
測されないといった条件を満たす難黒鉛化性炭素材料を
用いるのが好ましい。このような結晶構造パラメータ，
物性パラメータを有する非黒鉛炭素材料は、リチウムド
ープ容量が大きいので、やはりエネルギー密度が向上す
る。As the non-graphite carbon material, the true density is 1.70 g / cm 3 or less, and the true density is determined by the X-ray diffraction method (0
It is preferable to use a non-graphitizable carbon material satisfying the conditions that the 02) plane spacing is 0.37 nm or more and the oxidation exothermic peak is not observed at 700 ° C. or more in differential thermal analysis in an air stream. Such crystal structure parameters,
Since the non-graphite carbon material having the physical property parameters has a large lithium doping capacity, the energy density is also improved.

【００８６】また、上述のような黒鉛と非黒鉛炭素材料
の共存体を負極材料とする場合において、電解液の主溶
媒としては炭酸エチレンを用いると、通常電解液の主溶
媒として用いられる炭酸プロピレンに比べて黒鉛に対し
て安定であるので、上記共存体の負極性能が十分に発揮
される。In the case where the coexisting body of graphite and the non-graphite carbon material is used as the negative electrode material, when ethylene carbonate is used as the main solvent of the electrolytic solution, propylene carbonate usually used as the main solvent of the electrolytic solution. Since it is more stable to graphite than that of No. 1, the negative electrode performance of the above coexisting body is sufficiently exhibited.

【００８７】さらに、ＥＣを主体とする非水溶媒に第２
の成分溶媒として鎖状炭酸エステル、より好ましくは非
対称鎖状炭酸エステルあるいはＭＥＣとＤＥＣの混合溶
媒を添加すると、高導電率が得られるとともに高温使用
時、低温使用時の信頼性が向上し、さらにリチウム金属
との反応が抑えられる。Furthermore, a second non-aqueous solvent containing EC as a main component is added.
If a chain ester carbonate, more preferably an asymmetric chain ester carbonate or a mixed solvent of MEC and DEC is added as a component solvent of, a high conductivity is obtained and reliability at the time of high temperature use and low temperature use is further improved. The reaction with lithium metal is suppressed.

【００８８】[0088]

【実施例】以下、本発明の具体的な実施例について説明
するが、本発明がこの実施例に限定されるものでないこ
とは言うまでもない。EXAMPLES Hereinafter, specific examples of the present invention will be described, but it goes without saying that the present invention is not limited to these examples.

【００８９】実験例１ まず、マダガスカル産天然黒鉛を粉砕して黒鉛粉末Ａを
作製した。 Experimental Example 1 First, natural graphite produced in Madagascar was pulverized to prepare graphite powder A.

【００９０】次に、以下のようにして非黒鉛炭素粉末１
を作製した。Ｈ／Ｃ原子比が０．６〜０．８の範囲の石
油ピッチを粉砕し、空気気流中で酸化処理して、炭素前
駆体を生成した。このとき生成された炭素前駆体の酸素
含有率は１５．４重量％である。この炭素前駆体を粉砕
し、そのうち１０ｇをルツボに充填し、窒素気流中、温
度５００℃で５時間保持した後、温度１１００℃にまで
昇温し、１時間熱処理を行うことで難黒鉛化性炭素粉末
（非黒鉛炭素粉末１）を生成した。Next, the non-graphite carbon powder 1 was prepared as follows.
Was produced. A petroleum pitch having an H / C atomic ratio of 0.6 to 0.8 was crushed and subjected to an oxidation treatment in an air stream to generate a carbon precursor. The oxygen content of the carbon precursor produced at this time is 15.4% by weight. This carbon precursor was crushed, 10 g of it was filled in a crucible, and the temperature was kept at 500 ° C. for 5 hours in a nitrogen stream, then the temperature was raised to 1100 ° C., and heat treatment was performed for 1 hour to make it difficult to graphitize. A carbon powder (non-graphite carbon powder 1) was produced.

【００９１】表１に上記黒鉛粉末Ａ、非黒鉛炭素粉末１
の真比重，（００２）面の面間隔，（００２）面のＣ軸
方向の結晶子厚さ及び平均粒径を示す。なお、物性パラ
メータ中、（００２）面の面間隔，（００２）面のＣ軸
方向の結晶子厚みは粉末Ｘ線回折法によって求めたもの
であり、真比重は溶媒にブタノールを使用した液相置換
法（ピクノメータ法）によって測定したものである。Table 1 shows the above graphite powder A and non-graphite carbon powder 1
The true specific gravity, the (002) plane spacing, the (002) plane crystallite thickness in the C-axis direction, and the average grain size are shown. In the physical property parameters, the interplanar spacing of the (002) plane and the crystallite thickness of the (002) plane in the C-axis direction were obtained by a powder X-ray diffraction method, and the true specific gravity was a liquid phase using butanol as a solvent. It is measured by the substitution method (pycnometer method).

【００９２】このようにして作製された黒鉛粉末Ａ，非
黒鉛炭素粉末１を各種比率で混合し、黒鉛−非黒鉛炭素
材料の共存体を調製した。そして、この共存体を負極材
料に用いて以下のようにしてコイン型の非水電解液二次
電池，円筒型の非水電解液二次電池を作製した。The graphite powder A and the non-graphite carbon powder 1 thus prepared were mixed at various ratios to prepare a graphite-non-graphite carbon material coexisting body. Then, using this coexistence body as a negative electrode material, a coin type non-aqueous electrolyte secondary battery and a cylindrical non-aqueous electrolyte secondary battery were produced as follows.

【００９３】（１）コイン型非水電解液二次電池の作製 上記共存体に対して、負極ミックス作製直前にＡｒ雰囲
気中、昇温速度約３０℃／分、到達温度６００℃、保持
時間１時間なる条件で前熱処理を施した。そして、この
前熱処理が施された共存体に、バインダーとなるポリフ
ッ化ビニリデンを１０重量％相当量加え、ジメチルホル
ムアミドを溶媒として混合，乾燥して負極ミックスを調
製した。(1) Manufacture of coin type non-aqueous electrolyte secondary battery For the above coexisting body, a temperature rising rate of about 30 ° C./minute, a reached temperature of 600 ° C., a holding time of 1 were set in an Ar atmosphere immediately before the preparation of the negative electrode mix. Pre-heat treatment was performed under the condition of time. Then, 10% by weight of polyvinylidene fluoride serving as a binder was added to the pre-heat-treated coexisting substance, and dimethylformamide was mixed as a solvent and dried to prepare a negative electrode mix.

【００９４】このようにして調製された負極ミックスの
うち３７ｍｇをＮｉメッシュとともに直径１５．５ｍｍ
の円筒型ペレットに成形した。そして、この円筒型ペレ
ットを負極電極として以下のセル構成に組み込みコイン
型の非水電解二次電池を作製した。 セル構成 セル寸法：直径２０ｍｍ，厚さ２．５ｍｍ 正極：Ｌｉ金属 セパレータ：ポリプロピレン多孔質膜 電解液：ＥＣとＤＥＣが１：１なる容量比で混合されて
なる混合溶媒にＬｉＰＦ6 を１ｍｏｌ／ｌなる濃度で溶
解したもの なお、これらの作業は、全て露点−４０℃以下の乾燥空
気中にて行った。37 mg of the negative electrode mix thus prepared was used together with Ni mesh to have a diameter of 15.5 mm.
Was molded into a cylindrical pellet. Then, a coin-type non-aqueous electrolytic secondary battery was manufactured by incorporating the cylindrical pellet as a negative electrode into the following cell structure. Cell configuration Cell dimensions: diameter 20 mm, thickness 2.5 mm Positive electrode: Li metal Separator: Polypropylene porous membrane Electrolyte: EC and DEC 1: 1 LiPF 6 in a mixed solvent mixed at a volume ratio of 1: 1 What was melt | dissolved in the following density | concentration In addition, all these operations were performed in the dry air of dew point -40 degreeC or less.

【００９５】（２）円筒型の非水電解液二次電池の作製 本実施例で作製する円筒型非水電解液二次電池の構成を
図１に示す。このような構成の円筒型非水電解液二次電
池を以下のようにして作製した。(2) Preparation of Cylindrical Non-Aqueous Electrolyte Secondary Battery FIG. 1 shows the structure of the cylindrical non-aqueous electrolyte secondary battery prepared in this example. A cylindrical non-aqueous electrolyte secondary battery having such a structure was produced as follows.

【００９６】まず、負極１を次のようにして作製した。
上記共存体９０重量部、結着材となるポリフッ化ビニリ
デン（ＰＶＤＦ）１０重量部を混合して負極合剤を調製
し、この負極合剤を溶剤となるＮ−メチルピロリドンに
分散させて負極合剤スラリー（ペースト状）を調製し
た。この調製された負極合剤スラリーを、負極集電体９
となる厚さ１０μｍの帯状の銅箔の両面に塗布、乾燥さ
せた後、圧縮成型して帯状負極１を作製した。First, the negative electrode 1 was manufactured as follows.
90 parts by weight of the coexisting body and 10 parts by weight of polyvinylidene fluoride (PVDF) as a binder are mixed to prepare a negative electrode mixture, and the negative electrode mixture is dispersed in N-methylpyrrolidone as a solvent to form a negative electrode mixture. An agent slurry (paste form) was prepared. The prepared negative electrode mixture slurry was used as a negative electrode current collector 9
A strip-shaped negative electrode 1 having a thickness of 10 μm was coated on both sides of the strip-shaped copper foil, dried, and compression-molded to produce a strip-shaped negative electrode 1.

【００９７】正極２を次のようにして作製した。炭酸リ
チウム０．５モルと炭酸コバルト１モルを混合し、空気
中、温度９００℃で５時間焼成することでＬｉＣｏＯ2
を生成した。このようにして生成されたＬｉＣｏＯ2 に
ついて、Ｘ線回折測定を行った結果、ＪＣＰＤＳファイ
ルに登録されたＬｉＣｏＯ2 のピークと良く一致してい
た。このＬｉＣｏＯ2 を粉砕して、５０％累積粒径が１
５μｍのＬｉＣｏＯ2 粉末とし、該ＬｉＣｏＯ2 粉末９
５重量部と炭酸リチウム粉末５重量部を混合してなる混
合粉末を９１重量部、導電材となるグラファイト６重量
部、結着材となるポリフッ化ビニリデン３重量部を混合
して正極合剤を調製し、Ｎ−メチルピロリドンに分散さ
せて正極合剤スラリー（ペースト状）を調製した。The positive electrode 2 was manufactured as follows. By mixing 0.5 mol of lithium carbonate and 1 mol of cobalt carbonate and baking in air at a temperature of 900 ° C. for 5 hours, LiCoO 2
Was generated. As a result of X-ray diffraction measurement of the LiCoO 2 thus produced, it was in good agreement with the peak of LiCoO 2 registered in the JCPDS file. This LiCoO 2 was crushed to give a 50% cumulative particle size of 1
5 μm LiCoO 2 powder, and the LiCoO 2 powder 9
91 parts by weight of mixed powder obtained by mixing 5 parts by weight and 5 parts by weight of lithium carbonate powder, 6 parts by weight of graphite as a conductive material, and 3 parts by weight of polyvinylidene fluoride as a binder are mixed to form a positive electrode mixture. It was prepared and dispersed in N-methylpyrrolidone to prepare a positive electrode mixture slurry (paste form).

【００９８】この正極合剤スラリーを正極集電体１０と
なる厚さ２０μｍの帯状のアルミニウム箔の両面に均一
に塗布し、乾燥させた後、圧縮成形して帯状正極２を作
製した。This positive electrode mixture slurry was uniformly applied to both sides of a 20 μm-thick strip-shaped aluminum foil to be the positive electrode current collector 10, dried and then compression-molded to produce a strip-shaped positive electrode 2.

【００９９】次いで、図１に示すように帯状負極１、帯
状正極２及び厚さ２５μｍの微多孔性ポリプロピレンフ
ィルムよりなるセパレータ３を、帯状負極１、セパレー
タ３、帯状正極２、セパレータ３の順に積層してから多
数回巻回し、外径１８ｍｍの渦巻型電極体を作製した。Then, as shown in FIG. 1, a strip negative electrode 1, a strip positive electrode 2, and a separator 3 made of a microporous polypropylene film having a thickness of 25 μm are laminated in this order on the strip negative electrode 1, the separator 3, the strip positive electrode 2, and the separator 3. Then, it was wound many times to produce a spiral electrode body having an outer diameter of 18 mm.

【０１００】このようにして作製した渦巻型電極体を、
ニッケルめっきを施した鉄製電池缶５に収納した。渦巻
式電極体の上下には絶縁板４を配設し、アルミニウム製
正極リード１２を正極集電体１０から導出して電池蓋７
に、ニッケル製負極１１を負極集電体９から導出して電
池缶５に溶接した。The spirally wound electrode body thus prepared was
It was housed in a nickel-plated iron battery can 5. Insulating plates 4 are arranged above and below the spirally wound electrode body, and the aluminum positive electrode lead 12 is led out from the positive electrode current collector 10 to remove the battery lid 7.
Then, the nickel negative electrode 11 was led out from the negative electrode current collector 9 and welded to the battery can 5.

【０１０１】この渦巻式電極体が収納された電池缶５の
中に、炭酸エチレンと炭酸ジエチルが１：１なる容量比
で混合された混合溶媒に、ＬｉＰＦ6 を１ｍｏｌ／ｌな
る濃度で溶解された電解液を注入した。次いで、電流遮
断機構を有する安全弁装置８並びに電池蓋７を電池缶５
にアスファルトで表面を塗布した絶縁封口ガスケット６
を介してかしめることによって固定し、直径１８ｍｍ，
高さ６５ｍｍの円筒型の非水電解液二次電池を作製し
た。LiPF 6 was dissolved at a concentration of 1 mol / l in a mixed solvent in which ethylene carbonate and diethyl carbonate were mixed at a volume ratio of 1: 1 in a battery can 5 in which the spiral electrode body was housed. Electrolyte was injected. Next, the safety valve device 8 having a current cutoff mechanism and the battery lid 7 are attached to the battery can 5.
Insulation sealing gasket 6 whose surface is coated with asphalt
Fixed by caulking through, diameter 18mm,
A cylindrical non-aqueous electrolyte secondary battery having a height of 65 mm was produced.

【０１０２】まず、作製されたコイン型の非水電解液二
次電池について、断続充放電法にて負極材料１ｇ当たり
の負極容量，容量ロス及び分極値を調べた。First, the coin type non-aqueous electrolyte secondary battery thus prepared was examined for the negative electrode capacity, capacity loss and polarization value per 1 g of the negative electrode material by the intermittent charge / discharge method.

【０１０３】すなわち、充電（負極へのリチウムのドー
プ）は、セル当たり０．５ｍＡの定電流で１時間充電を
行った後、２時間休止を行うといった充電／休止サイク
ルを、休止時において測定される電位変化を（時間）
-1/2に対してプロットすることによって推定される平衡
電位が３〜１５ｍＶ（Ｌｉ／Ｌｉ+ ）になるまで繰り返
すことによって行った。That is, the charging (doping of lithium into the negative electrode) was measured during a rest period by performing a charge / pause cycle in which the cell was charged at a constant current of 0.5 mA for 1 hour and then paused for 2 hours. Potential change (time)
This was done by repeating until the equilibrium potential estimated by plotting against -1/2 was 3-15 mV (Li / Li + ).

【０１０４】放電（負極からのリチウムの脱ドープ）
は、セル当たり０．５ｍＡの定電流で１時間放電を行っ
た後、２時間休止を行うといった放電／休止サイクルを
端電圧が１．５Ｖになるまで繰り返すことによって行っ
た。Discharge (dedoping of lithium from the negative electrode)
Was carried out by repeating a discharge / pause cycle in which a constant current of 0.5 mA per cell was discharged for 1 hour and then a pause was carried out for 2 hours until the end voltage reached 1.5V.

【０１０５】容量ロスは、充電電気量から放電電気量を
差し引くことによって求めた。放電電気量は、いかなる
負極材料を用いた場合でも充電電気量よりも小さくなる
ことが知られており、ここでは、この充電されたが放電
されない電気容量を便宜上容量ロスと称することとす
る。The capacity loss was obtained by subtracting the discharged electricity quantity from the charged electricity quantity. It is known that the amount of discharged electricity is smaller than the amount of charged electricity regardless of the use of any negative electrode material. Here, the charged electrical capacity that is not discharged is referred to as capacity loss for convenience.

【０１０６】分極値は、負極炭素粉末１ｇ当たり約２５
０ｍＡｈの電気量を充電したきとの通電終了時の電位と
平衡電位の差から求めた。黒鉛粉末Ａのみを負極材料と
して用いた電池及び非黒鉛炭素粉末１のみを負極材料と
して用いた電池で測定された黒鉛粉末Ａ，非黒鉛炭素材
料１の１ｇ当たりの負極容量，容量ロスを物性パラメー
タと併せて表１に示す。The polarization value was about 25 per 1 g of the negative electrode carbon powder.
The amount of electricity of 0 mAh was calculated from the difference between the potential at the end of energization and the equilibrium potential. Negative electrode capacity and capacity loss per 1 g of graphite powder A and non-graphite carbon material 1 measured in a battery using only graphite powder A as a negative electrode material and a battery using only non-graphite carbon powder 1 as a negative electrode material are physical property parameters. The results are shown in Table 1.

【０１０７】[0107]

【表１】 [Table 1]

【０１０８】また、共存体全体に対する非黒鉛炭素粉末
１の割合と、負極容量，容量ロス及び分極値の関係を図
２に示す。FIG. 2 shows the relationship between the ratio of the non-graphite carbon powder 1 to the whole coexisting body, the negative electrode capacity, the capacity loss and the polarization value.

【０１０９】一方、円筒型の非水電解液二次電池には、
最大充電電圧４．２Ｖ，充電電流１Ａの条件で充電を
２．５時間行い、６．２Ωの定抵抗で放電を行うといっ
た充放電サイクルを繰り返し行って放電容量を測定し、
放電容量が初期容量の５０％にまで低下するサイクル数
（５０％容量サイクル数）及び電池初期容量比を調べ
た。共存体の全体に対する非黒鉛炭素粉末１の割合と、
５０％容量サイクル数、電池初期容量比の関係を図３に
示す。On the other hand, in the cylindrical non-aqueous electrolyte secondary battery,
Charging is performed for 2.5 hours under the conditions of maximum charging voltage 4.2V and charging current 1A, and discharging is performed with a constant resistance of 6.2Ω, and the discharge capacity is measured by repeating the charging / discharging cycle.
The cycle number at which the discharge capacity decreased to 50% of the initial capacity (50% capacity cycle number) and the battery initial capacity ratio were examined. The ratio of the non-graphite carbon powder 1 to the whole coexisting body,
FIG. 3 shows the relationship between the 50% capacity cycle number and the initial capacity ratio of the battery.

【０１１０】まず、図２を見てわかるように、負極容
量，容量ロスは、共存体全体に対する非黒鉛炭素粉末１
の割合が大きくなるのに伴って徐々に増大し、充電後の
分極値は、逆に共存体全体に対する非黒鉛炭素粉末１の
割合が大きくなるのに伴って大きく低下する。First, as can be seen from FIG. 2, the negative electrode capacity and the capacity loss are as follows:
Of the non-graphite carbon powder 1 with respect to the entire coexisting body, the polarization value after charging is greatly reduced.

【０１１１】さらに、図３において電池の５０％容量サ
イクル数を見ると、電池の５０％容量サイクル数は共存
体全体に対する非黒鉛炭素粉末１の割合が大きくなるの
に伴って増大し、サイクル劣化が起こり難くなってい
る。このように共存体中の非黒鉛炭素粉末の割合が大き
くなると、サイクル劣化が起こり難くなるのは、黒鉛を
多く含む負極、特に黒鉛単独で構成される負極では、負
極が充電に際して大きく分極するため、負極表面にリチ
ウム金属が析出するが、非黒鉛炭素材料を多く含む負極
の場合には、充電に際する分極が小さく、リチウム金属
の析出が生じ難いからである。Further, looking at the 50% capacity cycle number of the battery in FIG. 3, the 50% capacity cycle number of the battery increases as the ratio of the non-graphite carbon powder 1 to the whole coexisting body increases, and the cycle deterioration occurs. Is less likely to occur. When the proportion of the non-graphite carbon powder in the coexisting substance becomes large in this way, cycle deterioration is less likely to occur because the negative electrode that contains a large amount of graphite, especially the negative electrode composed of graphite alone, is greatly polarized during charging. This is because lithium metal is deposited on the surface of the negative electrode, but in the case of a negative electrode containing a large amount of non-graphite carbon material, the polarization during charging is small and the precipitation of lithium metal is less likely to occur.

【０１１２】しかし、図３において電池の初期容量比を
見ると、電池の初期容量比は、活物質中の難黒鉛化性炭
素粉末の含有比率が大きくなるのに伴って小さくなり、
負極が難黒鉛化性炭素を多く含む場合、特に難黒鉛化性
炭素単独で構成されている場合には、高いエネルギー密
度が得られないことがわかる。However, looking at the initial capacity ratio of the battery in FIG. 3, the initial capacity ratio of the battery decreases as the content ratio of the non-graphitizable carbon powder in the active material increases,
It can be seen that a high energy density cannot be obtained when the negative electrode contains a large amount of non-graphitizable carbon, particularly when it is composed of non-graphitizable carbon alone.

【０１１３】以上のことから、サイクル特性，エネルギ
ー密度のいずれにおいても優れる非水電解液二次電池を
得るには、負極を黒鉛単独あるいは非黒鉛炭素材料単独
で構成せずに、黒鉛と非黒鉛炭素材料を共存させること
が必要であることがわかる。なお、この場合、黒鉛材料
と非黒鉛炭素材料の混合率は、黒鉛材料の混合率が大き
くなると電池容量が増大し、非黒鉛炭素材料の混合率が
大きくなると充放電サイクル特性が改善されるといった
傾向を考慮しつつ、用途に応じて即ちどちらの特性を重
要視する必要があるかによって選択することが望まし
い。実用的には共存体全体に対する非黒鉛炭素材料の割
合は１０％以上９０％以下、好ましくは２０％以上８０
％以下の範囲が良い。From the above, in order to obtain a non-aqueous electrolyte secondary battery which is excellent in both cycle characteristics and energy density, graphite and non-graphite should be used without forming the negative electrode with graphite alone or non-graphite carbon material alone. It turns out that it is necessary to coexist with a carbon material. In this case, regarding the mixing ratio of the graphite material and the non-graphite carbon material, the battery capacity increases when the mixing ratio of the graphite material increases, and the charge-discharge cycle characteristics improve when the mixing ratio of the non-graphite carbon material increases. It is desirable to make a selection depending on the application, that is, which characteristic needs to be emphasized while considering the tendency. Practically, the ratio of the non-graphite carbon material to the whole coexisting material is 10% or more and 90% or less, preferably 20% or more and 80% or more.
% Or less is preferable.

【０１１４】実験例２ 本実験例では、負極に用いる黒鉛，非黒鉛炭素材料の種
類を変化させ、充放電サイクル特性，電池容量を比較し
た。本実験例で用いた黒鉛及び非黒鉛炭素材料を以下に
示す。 Experimental Example 2 In this experimental example, the types of graphite and non-graphite carbon materials used for the negative electrode were changed, and the charge / discharge cycle characteristics and the battery capacity were compared. The graphite and non-graphite carbon materials used in this experimental example are shown below.

【０１１５】黒鉛：マダカスカル産天然黒鉛粉末（黒鉛
粉末Ａ） ロンザ社製人造黒鉛粉末（黒鉛粉末Ｂ） 非黒鉛炭素材料：非黒鉛炭素粉末２〜非黒鉛炭素粉末
７、但し、これら非黒鉛炭素粉末２〜非黒鉛炭素粉末７
は以下のようにして生成されたものである。Graphite: Natural graphite powder from Madacascal (graphite powder A) Artificial graphite powder (graphite powder B) manufactured by Lonza Co. Non-graphite carbon material: non-graphite carbon powder 2 to non-graphite carbon powder 7, provided that these non-graphite carbon powders 2 to non-graphite carbon powder 7
Is generated as follows.

【０１１６】（１）非黒鉛炭素粉末２，非黒鉛炭素粉末
３ 原料となる石炭ピッチを、窒素気流中，温度５００℃で
５時間保持した後、１２００〜１４００℃まで昇温し、
１時間熱処理することで生成した。(1) Non-graphite carbon powder 2 and non-graphite carbon powder 3 The raw material coal pitch was held in a nitrogen stream at a temperature of 500 ° C. for 5 hours and then heated to 1200 to 1400 ° C.
It was generated by heat treatment for 1 hour.

【０１１７】（２）非黒鉛炭素粉末４ 原料となる石油ピッチを、窒素気流中，温度５００℃で
５時間保持した後、１２００℃まで昇温し、１時間熱処
理することで生成した。(2) Non-graphite carbon powder 4 It was produced by holding petroleum pitch as a raw material in a nitrogen stream at a temperature of 500 ° C for 5 hours, then raising it to 1200 ° C and heat-treating it for 1 hour.

【０１１８】（３）非黒鉛炭素粉末５，非黒鉛炭素粉末
６ Ｈ／Ｃ原子比が０．６〜０．８の範囲から選んだ石油ピ
ッチを粉砕し、空気気流中、酸化処理することで炭素前
駆体を得た。この炭素前駆体の酸素含有率を有機元素分
析法によって測定したところ、１５〜１８重量％であっ
た。この炭素前駆体を粉砕し、窒素気流中，温度５００
℃で５時間保持した後、１１００〜１２００℃まで昇温
し、１時間熱処理することで生成した。(3) Non-graphite carbon powder 5, non-graphite carbon powder 6 By crushing petroleum pitch selected from the range of H / C atomic ratio of 0.6 to 0.8, and oxidizing it in an air stream. A carbon precursor was obtained. When the oxygen content of this carbon precursor was measured by an organic elemental analysis method, it was 15 to 18% by weight. This carbon precursor is crushed and heated in a nitrogen stream at a temperature of 500.
After holding at 5 ° C. for 5 hours, the temperature was raised to 1100 to 1200 ° C., and heat treatment was performed for 1 hour.

【０１１９】（４）非黒鉛炭素粉末７ 原料となるフルフリルアルコール樹脂を、窒素気流中，
温度５００℃で５時間保持した後、１２００℃まで昇温
し、１時間熱処理することで生成した。以上、黒鉛粉末
１，黒鉛粉末２及び非黒鉛炭素粉末２〜非黒鉛炭素粉末
７の（００２）面の面間隔，（００２）面のＣ軸方向の
結晶子厚み，真比重を表２に示す。(4) Non-graphite carbon powder 7 Furfuryl alcohol resin as a raw material was placed in a nitrogen stream,
After being kept at a temperature of 500 ° C. for 5 hours, the temperature was raised to 1200 ° C. and heat treatment was performed for 1 hour. As described above, Table 2 shows the (002) plane spacing, the (002) plane crystallite thickness in the C-axis direction, and the true specific gravity of each of the graphite powder 1, the graphite powder 2, and the non-graphite carbon powder 2 to the non-graphite carbon powder 7. .

【０１２０】まず、上記黒鉛粉末Ａ，黒鉛粉末Ｂと非黒
鉛炭素粉末２〜非黒鉛炭素粉末７をそれぞれ負極材料と
して実験例１に準じた構成でコイン型非水電解液二次電
池を作成した。そして、断続充放電法にて１ｇ当たりの
負極容量，分極値を測定するとともに放電カーブの平坦
性を評価するために、リチウム電位を基準として、０．
３Ｖの電位までの放電容量と１．５Ｖの電位までの放電
容量の比を求めた。これら負極特性の測定結果を、上記
物性パラメータと併せて表２に示す。First, a coin-type non-aqueous electrolyte secondary battery was prepared by using the above graphite powder A, graphite powder B and non-graphite carbon powder 2 to non-graphite carbon powder 7 as negative electrode materials and in a structure according to Experimental Example 1. . Then, in order to measure the negative electrode capacity per 1 g and the polarization value by the intermittent charging / discharging method, and to evaluate the flatness of the discharge curve, the lithium potential was used as a reference and the value of 0.
The ratio of the discharge capacity up to the potential of 3V and the discharge capacity up to the potential of 1.5V was determined. The measurement results of these negative electrode characteristics are shown in Table 2 together with the above physical property parameters.

【０１２１】[0121]

【表２】 [Table 2]

【０１２２】次に、上記黒鉛粉末Ａ，黒鉛粉末Ｂと非黒
鉛炭素粉末２〜非黒鉛炭素粉末７を組み合わせて各種混
合率で混合し、この黒鉛−非黒鉛炭素材料の共存体を負
極材料として非水電解液二次電池（電池２−１〜電池２
−１０及び比較電池２−１〜比較電池２−３）をコイン
型，円筒型で実験例１に準じて作成した。各電池の負極
材料として用いた共存体の種類，混合率を表３に示す。Next, the graphite powder A, the graphite powder B and the non-graphite carbon powder 2 to non-graphite carbon powder 7 were combined and mixed at various mixing ratios, and the coexisting body of the graphite-non-graphite carbon material was used as a negative electrode material. Non-aqueous electrolyte secondary battery (battery 2-1 to battery 2
-10 and Comparative Battery 2-1 to Comparative Battery 2-3) were coin type and cylindrical type and were prepared according to Experimental Example 1. Table 3 shows the types and mixing ratios of the coexisting substances used as the negative electrode material of each battery.

【０１２３】そして、コイン型の電池を用い、断続充放
電法にて負極材料の分極値を測定した。測定された分極
値，初期電池容量を、用いた共存体の種類，混合率と併
せて表３に示す。Then, using a coin type battery, the polarization value of the negative electrode material was measured by the intermittent charge / discharge method. Table 3 shows the measured polarization value and initial battery capacity together with the type of coexisting substance used and the mixing ratio.

【０１２４】[0124]

【表３】 [Table 3]

【０１２５】また、円筒型の電池には、上限電圧を４．
２Ｖ，定電流領域での電流１Ａの条件で定電圧定電流法
による充電を２．５時間行った後、電流０．５Ａ，終止
電圧２．７５Ｖの条件で定電流放電を行うといった充放
電サイクルを繰り返し行い、サイクル毎の電池容量を測
定することで調査した。In addition, the upper limit voltage of the cylindrical battery is 4.
Charging / discharging cycle in which charging is performed by the constant voltage constant current method for 2.5 hours under the condition of 2 V and current 1 A in the constant current region, and then constant current discharge is performed under the condition of current 0.5 A and final voltage 2.75 V. Was repeated and the battery capacity was measured for each cycle for the investigation.

【０１２６】充放電サイクル数と電池容量の関係を図４
〜図６に示す。なお、図４は、用いた黒鉛粉末，非黒鉛
炭素材料の種類は同じであるが（いずれも黒鉛粉末Ａと
非黒鉛炭素粉末６）、その混合率が異なる電池の充放電
サイクル特性を併せて示すものであり、図５は、黒鉛と
非黒鉛炭素材料の混合率は同じであるが（いずれも５０
重量部：５０重量部）、非黒鉛炭素材料の種類が異なる
電池の充放電サイクル特性を併せて示すものであり、図
６は、黒鉛として人造黒鉛（黒鉛粉末Ｂ）を用いた電池
の充放電サイクル特性を併せて示すものである。但し、
各図中、縦軸の容量比は初期容量を１００％としたとき
の相対値である。FIG. 4 shows the relationship between the number of charge / discharge cycles and the battery capacity.
~ Shown in FIG. In addition, in FIG. 4, the types of the graphite powder and the non-graphite carbon material used are the same (both the graphite powder A and the non-graphite carbon powder 6), but the charge-discharge cycle characteristics of the batteries having different mixing ratios are also shown. FIG. 5 shows that the mixing ratios of graphite and non-graphite carbon materials are the same (50% for both).
(Parts by weight: 50 parts by weight) and charge / discharge cycle characteristics of batteries having different types of non-graphite carbon materials are also shown. FIG. 6 shows charge / discharge of batteries using artificial graphite (graphite powder B) as graphite. The cycle characteristics are also shown. However,
In each figure, the capacity ratio on the vertical axis is a relative value when the initial capacity is 100%.

【０１２７】まず、図４を見ると、黒鉛粉末Ａと非黒鉛
炭素粉末６の共存体を負極に用いた電池（電池２−１〜
電池２−４）は、黒鉛粉末Ａを単独で負極に用いた電池
（比較電池２−１）に比べて充放電サイクル特性の進行
に伴った容量劣化が小さく、また表３に示すように非黒
鉛炭素粉末６を単独で負極に用いた電池（比較電池２−
２）に比べて初期電池容量が大なるものとなっている。
また、黒鉛粉末Ａと非黒鉛炭素粉末６の共存体を負極に
用いる場合では、共存体中の非黒鉛炭素粉末６の割合が
大きくなる程、充放電サイクル特性は向上し、その反面
電池容量は小さくなる。First, referring to FIG. 4, a battery using a coexisting body of graphite powder A and non-graphite carbon powder 6 as a negative electrode (Batteries 2-1 to 2-1)
The battery 2-4) showed less capacity deterioration with progress of charge / discharge cycle characteristics than the battery (comparative battery 2-1) in which the graphite powder A alone was used for the negative electrode, and as shown in Table 3, Batteries using graphite carbon powder 6 alone as a negative electrode (Comparative Battery 2-
The initial battery capacity is larger than that in 2).
When a coexisting body of the graphite powder A and the non-graphite carbon powder 6 is used for the negative electrode, the higher the ratio of the non-graphite carbon powder 6 in the coexisting body is, the higher the charge / discharge cycle characteristics are. Get smaller.

【０１２８】これらの結果は、いずれも実験例１の結果
と合致するものであり、このことからも黒鉛材料と非黒
鉛炭素材料が適度な比率で混合されてなる共存体を負極
に用いることは、電池容量が大きく、且つ充放電サイク
ル特性に優れた電池を得る上で有効であることがわか
る。All of these results are in agreement with the results of Experimental Example 1, and also from this fact, it is not possible to use a coexisting body in which a graphite material and a non-graphite carbon material are mixed in an appropriate ratio for the negative electrode. It can be seen that it is effective in obtaining a battery having a large battery capacity and excellent charge / discharge cycle characteristics.

【０１２９】次に、図５を見ると、電池２−５〜電池２
−９は、いずれも負極材料として黒鉛と非黒鉛炭素材料
の共存体を用いており、その混合率も同じく設定してい
るが、黒鉛と組み合わせた非黒鉛炭素材料の種類が異な
っており、これにより充放電サイクル特性に著しい差が
認められる。Next, referring to FIG. 5, battery 2-5 to battery 2
No. 9 uses a coexisting body of graphite and a non-graphite carbon material as a negative electrode material, and the mixing ratio is set similarly, but the type of the non-graphite carbon material combined with graphite is different. As a result, a significant difference is observed in the charge / discharge cycle characteristics.

【０１３０】すなわち、表２に示す断続充放電法によっ
て測定された負極容量が、同様にして測定された黒鉛材
料Ａの負極容量の８０％（２５６ｍＡｈ／ｇ）より小さ
い非黒鉛炭素粉末２を用いた電池２−５は、黒鉛粉末Ａ
を単独で負極に用いた比較電池２−１に比べればサイク
ル特性は向上しているもののその傾向はあまり顕著では
ない。That is, the non-graphite carbon powder 2 whose negative electrode capacity measured by the intermittent charge / discharge method shown in Table 2 is smaller than 80% (256 mAh / g) of the negative electrode capacity of the graphite material A measured in the same manner is used. Batteries 2-5 were graphite powder A
Although the cycle characteristics are improved as compared with the comparative battery 2-1 in which the battery is used alone as the negative electrode, the tendency is not so remarkable.

【０１３１】これに対して、断続充放電法によって測定
された負極容量が、同様にして測定された黒鉛材料Ａの
負極容量の８０％以上の非黒鉛炭素材料（非黒鉛炭素粉
末３〜非黒鉛炭素粉末７）を用いた電池２−６〜電池２
−９は、比較電池２−１に比べてサイクル特性が大きく
改善されている。さらに、放電カーブの平坦性がよい非
黒鉛炭素材料、すなわち、表２に示す０．３Ｖまでの放
電容量の１．５Ｖまでの放電容量に対する比が０．５以
上の非黒鉛炭素材料（非黒鉛炭素粉末４〜非黒鉛炭素粉
末７）を用いた電池２−７〜電池２−９、さらに０．３
Ｖまでの放電容量の１．５Ｖまでの放電容量に対する比
が０．５以上であって、断続充放電法によって測定され
た負極容量が、同様にして測定された黒鉛粉末Ａの負極
容量の９０％（２８８ｍＡｈ／ｇ）以上の非黒鉛炭素材
料（非黒鉛炭素粉末５〜非黒鉛炭素粉末７）を用いた電
池２−８，電池２−９は、非常に優れたサイクル特性を
示す。On the other hand, the negative electrode capacity measured by the intermittent charging / discharging method is 80% or more of the negative electrode capacity of the graphite material A measured in the same manner. Battery 2-6 to Battery 2 using carbon powder 7)
In No. 9, the cycle characteristics are greatly improved as compared with Comparative Battery 2-1. Further, a non-graphite carbon material having a good discharge curve flatness, that is, a non-graphite carbon material (non-graphite carbon material having a ratio of the discharge capacity up to 0.3 V to the discharge capacity up to 1.5 V shown in Table 2 of 0.5 or more (non-graphite Battery 2-7 to Battery 2-9 using carbon powder 4 to non-graphite carbon powder 7), and 0.3
The ratio of the discharge capacity up to V to the discharge capacity up to 1.5 V is 0.5 or more, and the negative electrode capacity measured by the intermittent charge / discharge method is 90% of the negative electrode capacity of the graphite powder A measured in the same manner. % (288 mAh / g) or more of the non-graphite carbon material (non-graphite carbon powder 5 to non-graphite carbon powder 7), Battery 2-8 and Battery 2-9 show very excellent cycle characteristics.

【０１３２】このことから、サイクル特性に優れた電池
を得るには、単に黒鉛と非黒鉛炭素材料を組み合わせる
のではなく、用いる非黒鉛炭素材料の負極容量，放電カ
ーブの平坦性も考慮することが望ましいことがわかる。Therefore, in order to obtain a battery having excellent cycle characteristics, it is necessary to consider not only the combination of graphite and a non-graphite carbon material but also the negative electrode capacity of the non-graphite carbon material used and the flatness of the discharge curve. I find it desirable.

【０１３３】最後に、図６を見ると、電池２−１０は、
負極に人造黒鉛である黒鉛粉末Ｂと非黒鉛炭素粉末６を
５０重量部：５０重量部なる割合で混合した共存体を用
いているが、天然黒鉛である黒鉛粉末Ａと非黒鉛炭素粉
末６を同じ混合率で混合した共存体を用いた電池２−２
と同程度に良好なサイクル特性が得られている。Finally, referring to FIG. 6, the battery 2-10 is
For the negative electrode, a coexisting body in which graphite powder B which is artificial graphite and non-graphite carbon powder 6 are mixed at a ratio of 50 parts by weight: 50 parts by weight is used. Graphite A which is natural graphite and non-graphite carbon powder 6 are used. Battery 2-2 using coexisting materials mixed at the same mixing ratio
The cycle characteristics are as good as those of.

【０１３４】このことから、黒鉛としては、天然黒鉛で
あっても人造黒鉛であっても差し支えなく、充放電サイ
クル特性は非黒鉛炭素材料の種類には依存するが黒鉛の
種類には依らないことがわかる。From this, it is possible to use natural graphite or artificial graphite as the graphite, and the charge / discharge cycle characteristics depend on the type of non-graphite carbon material, but not on the type of graphite. I understand.

【０１３５】実験例３ 本実験例では、別々に作成された黒鉛粉末と非黒鉛炭素
材料粉末を混合して調製された共存体を負極に供する場
合、黒鉛と非黒鉛炭素材料よりなる複合炭素材料を生成
し、この複合炭素材料を粉砕することで得た共存体を負
極に供する場合について、５０％容量サイクル数を比較
した。さらに、非水電解液を各種変化させて過充電時の
温度上昇を比較した。 Experimental Example 3 In this experimental example, when a coexisting body prepared by mixing separately prepared graphite powder and non-graphite carbon material powder is used for the negative electrode, a composite carbon material composed of graphite and non-graphite carbon material is used. Was produced and the coexistent obtained by pulverizing this composite carbon material was used for the negative electrode, and the 50% capacity cycle numbers were compared. Furthermore, various changes in the non-aqueous electrolyte were compared to compare the temperature rise during overcharge.

【０１３６】本実験例で用いた共存体の調製方法を以下
に示す。The method for preparing the coexisting body used in this experimental example is shown below.

【０１３７】（１）共存体１ 黒鉛材料粉末１と非黒鉛炭素材料粉末１を６：４なる混
合比率で混合することで調製した。(1) Coexistence body 1 It was prepared by mixing the graphite material powder 1 and the non-graphite carbon material powder 1 in a mixing ratio of 6: 4.

【０１３８】（２）共存体２ フルフリルアルコール１００重量部、濃度８５％のリン
酸０．５重量部、水１０重量部を混合してなる混合液を
湯浴上で５時間加熱して、粘稠性を有する重合体（フル
フリルアルコール樹脂）を合成した。なお、合成反応に
関与せずに残留した水及び未反応なアルコールは真空蒸
留法にて除去した。(2) Coexisting body 2 A mixed solution obtained by mixing 100 parts by weight of furfuryl alcohol, 0.5 parts by weight of phosphoric acid having a concentration of 85%, and 10 parts by weight of water is heated on a hot water bath for 5 hours, A viscous polymer (furfuryl alcohol resin) was synthesized. Water and unreacted alcohol remaining without participating in the synthesis reaction were removed by vacuum distillation.

【０１３９】合成されたフルフリルアルコール樹脂１０
０重量部に、マダカスカル産天然黒鉛を粉砕してなる黒
鉛粉末１６重量部を添加し、このうち１００ｇを採取し
て湯浴上で十分混合した。そして、この混合物を、窒素
気流中、温度５００℃で５時間炭化し、さらに温度１１
００℃まで昇温して１時間熱処理することで約３５ｇの
複合炭素材料を生成した。この複合炭素材料を粉砕する
ことで調製した。Synthesized furfuryl alcohol resin 10
To 0 parts by weight, 16 parts by weight of graphite powder obtained by crushing Madagascar natural graphite was added, and 100 g of this was collected and thoroughly mixed in a hot water bath. Then, this mixture was carbonized in a nitrogen stream at a temperature of 500 ° C. for 5 hours, and further heated to a temperature of 11
About 35 g of composite carbon material was produced by heating to 00 ° C. and heat treatment for 1 hour. It was prepared by crushing this composite carbon material.

【０１４０】この複合炭素粉末について、粉末Ｘ線回折
法にて観測される（００２）面の回折ピークを分離する
ことによって、成分比率を求めた結果、黒鉛と難黒鉛化
性炭素の比率は６：４であった。The component ratio of this composite carbon powder was determined by separating the diffraction peak of the (002) plane observed by the powder X-ray diffraction method. As a result, the ratio of graphite to non-graphitizable carbon was 6 : It was 4.

【０１４１】（３）共存体３ 共存体２を調製するのと同様にして合成されたフルフリ
ルアルコール樹脂に、濃度８５％のリン酸４重量部を添
加し、窒素気流中、温度５００℃で５時間炭化し、さら
に温度１１００℃まで昇温して１時間熱処理することで
リン、酸素、炭素を主体とする難黒鉛化性炭素を生成し
た。(3) Coexisting body 3 To a furfuryl alcohol resin synthesized in the same manner as in preparing the coexisting body 2, 4 parts by weight of phosphoric acid having a concentration of 85% was added, and the temperature was 500 ° C. in a nitrogen stream. It was carbonized for 5 hours, further heated to a temperature of 1100 ° C. and heat-treated for 1 hour to produce non-graphitizable carbon mainly containing phosphorus, oxygen and carbon.

【０１４２】マダカスカル産天然黒鉛を粉砕してなる黒
鉛粉末とこのようにして生成された難黒鉛化性炭素を
６：４なる混合比率で十分混合することで調製した。 （4)共存体４ 共存体２を調製するのと同様にして合成されたフルフリ
ルアルコール樹脂に対し、平均粒径約５μｍの金属鉄粒
子を１０重量％添加し、温度１００℃程度で加熱した。
そして、樹脂が液状を呈したところでよく攪拌し、鉄粒
子を分散させた。この混合物を、窒素気流中、温度５０
０℃で５時間炭化し、さらに１２００℃まで昇温し、１
時間熱処理することで、難黒鉛化性炭素材料の一部が黒
鉛相に変化した非黒鉛炭素材料と黒鉛材料の共存体を得
た。It was prepared by thoroughly mixing graphite powder obtained by pulverizing natural graphite produced in Madagascar and the non-graphitizable carbon thus produced in a mixing ratio of 6: 4. (4) Coexistence body 4 To the furfuryl alcohol resin synthesized in the same manner as in preparation of coexistence body 2, 10% by weight of metallic iron particles having an average particle size of about 5 μm was added and heated at a temperature of about 100 ° C. .
Then, when the resin was in a liquid state, it was well stirred to disperse the iron particles. This mixture was heated to a temperature of 50 in a nitrogen stream.
Carbonize at 0 ° C for 5 hours, further raise the temperature to 1200 ° C, and
By heat treatment for a long time, a coexistence body of a non-graphite carbon material and a graphite material in which a part of the non-graphitizable carbon material was changed to a graphite phase was obtained.

【０１４３】なお、この共存体について、粉末Ｘ線回折
法にて観測される（００２）面の回折ピークを分離する
ことで成分比率を求めた結果、黒鉛と難黒鉛化性炭素材
料の比率は約５：５であった。The component ratio of this coexistence substance was determined by separating the diffraction peak of the (002) plane observed by the powder X-ray diffraction method. As a result, the ratio of graphite to the non-graphitizable carbon material was found to be It was about 5: 5.

【０１４４】また、本実験例で用いた非水電解液を以下
に示す。The non-aqueous electrolyte used in this experimental example is shown below.

【０１４５】（４）非水電解液１ ＥＣとＤＥＣを、ＥＣ：ＤＥＣ＝１：１なる容量比で混
合し、この混合溶媒にＬｉＰＦ6 を１ｍｏｌ／ｌなる濃
度で溶解することで調製した。(4) Non-Aqueous Electrolyte Solution 1 EC and DEC were mixed at a volume ratio of EC: DEC = 1: 1, and LiPF 6 was dissolved in this mixed solvent at a concentration of 1 mol / l.

【０１４６】（５）非水電解液２ ＥＣとＭＥＣを、ＥＣ：ＭＥＣ＝１：１なる容量比で混
合し、この混合溶媒にＬｉＰＦ6 を１ｍｏｌ／ｌなる濃
度で溶解することで調製した。(5) Non-Aqueous Electrolyte Solution 2 EC and MEC were mixed at a volume ratio of EC: MEC = 1: 1, and LiPF 6 was dissolved in this mixed solvent at a concentration of 1 mol / l.

【０１４７】（６）非水電解液３ ＥＣ，ＭＥＣ及びＤＭＣを、ＥＣ：ＭＥＣ：ＤＭＣ＝
５：３：２なる容量比で混合し、この混合溶媒にＬｉＰ
Ｆ6 を１ｍｏｌ／ｌなる濃度で溶解することで調製し
た。(6) Nonaqueous Electrolyte Solution 3 EC, MEC and DMC are replaced by EC: MEC: DMC =
Mix in a volume ratio of 5: 3: 2 and add LiP to the mixed solvent.
It was prepared by dissolving F 6 at a concentration of 1 mol / l.

【０１４８】これら共存体，非水電解液を用いて実験例
１に準じて円筒型非水電解液二次電池（電池３−１〜電
池３−６）を作成した。各電池の用いた共存体，非水電
解液を表４に示す。Cylindrical non-aqueous electrolyte secondary batteries (Battery 3-1 to Battery 3-6) were prepared in accordance with Experimental Example 1 using these coexisting substances and the non-aqueous electrolyte. Table 4 shows the coexisting substances and non-aqueous electrolyte used in each battery.

【０１４９】[0149]

【表４】 [Table 4]

【０１５０】そして、作成された電池について、最大充
電電圧４．２Ｖ，充電電流１Ａの条件で充電を２．５時
間行い、６．２Ωの定抵抗で放電を行うといった充放電
サイクルを繰り返し行って放電容量を測定し、放電容量
が初期容量の５０％にまで低下するサイクル数（５０％
容量サイクル数）を調べた。また、電流３．７Ａで定電
流充電を行うことで過充電状態にし、過充電による電流
遮断装置作動後の電池表面の温度変化を調べた。５０％
容量サイクル数及び過充電時の最高温度を表５に示す。The battery thus prepared was repeatedly charged and discharged for 2.5 hours under the conditions of maximum charging voltage 4.2V and charging current 1A and discharging with a constant resistance of 6.2Ω. The discharge capacity is measured, and the number of cycles (50%) at which the discharge capacity drops to 50% of the initial capacity.
The capacity cycle number) was investigated. In addition, a constant current charge was performed at a current of 3.7 A to bring the battery into an overcharged state, and the temperature change on the battery surface after the operation of the current interrupt device due to overcharge was examined. 50%
Table 5 shows the number of capacity cycles and the maximum temperature during overcharge.

【０１５１】[0151]

【表５】 [Table 5]

【０１５２】表５から、黒鉛粉末と難黒鉛化性炭素粉末
を含有する炭素粉末を負極材料とする電池３−１〜電池
３−６は、実験例１において黒鉛のみを負極材料として
用いた場合（例えば図３を参照した場合、５０％容量サ
イクル数は約６０回である）に比べていずれも５０％容
量サイクル数が格段に大きく良好なサイクル特性を示す
ことがわかる。From Table 5, the batteries 3-1 to 3-6 using the carbon powder containing the graphite powder and the non-graphitizable carbon powder as the negative electrode material were the same as those in Experimental Example 1 except that only graphite was used as the negative electrode material. It can be seen that the 50% capacity cycle number is significantly larger than that of the case of FIG. 3 (for example, the 50% capacity cycle number is about 60 times), and good cycle characteristics are exhibited.

【０１５３】このことから、非水電解液二次電池におい
ては、黒鉛と非黒鉛炭素材料の共存体であれば、炭素粉
末としては黒鉛粉末と難黒鉛化性炭素粉末を混合してな
る混合炭素粉末であっても、黒鉛と難黒鉛化性炭素の複
合炭素を粉砕してなる複合炭素粉末であっても良く、い
すれの場合にも同様にサイクル特性，電池容量の向上が
図れることがわかる。Therefore, in the non-aqueous electrolyte secondary battery, if the graphite and the non-graphite carbon material coexist, the carbon powder is a mixed carbon obtained by mixing the graphite powder and the non-graphitizable carbon powder. It may be a powder or a composite carbon powder obtained by pulverizing composite carbon of graphite and non-graphitizable carbon. It can be seen that the cycle characteristics and the battery capacity can be similarly improved in any case. .

【０１５４】また、過充電時最高温度を比較すると電池
３−１に比べて電池３−５，電池３−６の方が過充電時
最高温度が低くなっており、安全性が高いことがわか
る。このことから、非水溶媒の主溶媒となるＥＣに添加
する第２の添加溶媒としては、ＤＥＣよりもＭＥＣやＭ
ＥＣ−ＤＭＣの混合溶媒が好ましいことがわかる。Further, comparing the maximum temperatures during overcharging, it can be seen that the maximum temperatures during overcharging of batteries 3-5 and 3-6 are lower than that of battery 3-1, indicating that the safety is high. . From this, as the second addition solvent to be added to EC that is the main solvent of the non-aqueous solvent, MEC and M are more preferable than DEC.
It can be seen that the mixed solvent of EC-DMC is preferable.

【０１５５】[0155]

【発明の効果】以上の説明からも明らかなように、本発
明の非水電解液二次電池では、負極材料として黒鉛と非
黒鉛炭素材料の共存体を用いるので、高い電極充填性を
有するとともに、充放電の際してリチウムイオンの拡散
速度が速く、さらに充電終止時の負極単体の電位が卑な
負極が得られ、エネルギー密度，サイクル特性，信頼性
に優れた非水電解液二次電池を得ることが可能である。As is clear from the above description, in the non-aqueous electrolyte secondary battery of the present invention, since a coexisting body of graphite and non-graphite carbon material is used as the negative electrode material, it has a high electrode filling property. , A non-aqueous electrolyte secondary battery that has a high diffusion rate of lithium ions during charge and discharge and a negative electrode with a negative base electrode potential at the end of charging, and has excellent energy density, cycle characteristics, and reliability. It is possible to obtain

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

【図１】本発明を適用する非水電解液二次電池の一構成
例を示す概略縦断面図である。FIG. 1 is a schematic vertical cross-sectional view showing one structural example of a non-aqueous electrolyte secondary battery to which the present invention is applied.

【図２】共存体中の非黒鉛炭素材料の割合と、負極材料
１ｇ当たりの容量，容量ロス及び充電後の分極値の関係
を示す特性図である。FIG. 2 is a characteristic diagram showing a relationship between a ratio of a non-graphite carbon material in a coexisting body, a capacity per 1 g of a negative electrode material, a capacity loss, and a polarization value after charging.

【図３】共存体中の非黒鉛炭素材料の割合と、５０％容
量サイクル数，電池初期容量比の関係を示す特性図であ
る。FIG. 3 is a characteristic diagram showing the relationship between the ratio of the non-graphite carbon material in the coexisting body, the 50% capacity cycle number, and the battery initial capacity ratio.

【図４】共存体中の非黒鉛炭素材料の割合が異なる電池
の、充放電サイクル数と容量比の関係を示す特性図であ
る。FIG. 4 is a characteristic diagram showing the relationship between the number of charge / discharge cycles and the capacity ratio of batteries in which the proportion of the non-graphite carbon material in the coexisting body is different.

【図５】非黒鉛炭素材料の種類が異なる電池の、充放電
サイクル数と容量比の関係を示す特性図である。FIG. 5 is a characteristic diagram showing the relationship between the number of charge / discharge cycles and the capacity ratio of batteries having different types of non-graphite carbon materials.

【図６】人造黒鉛を用いた電池の、充放電サイクル数と
容量比の関係を示す特性図である。FIG. 6 is a characteristic diagram showing the relationship between the number of charge / discharge cycles and the capacity ratio of a battery using artificial graphite.

【符号の説明】[Explanation of symbols]

１・・・負極 ２・・・正極 ３・・・セパレータ ４・・・絶縁板 ５・・・電池缶 ６・・・絶縁封口ガスケット ７・・・電池蓋 ８・・・安全弁装置 ９・・・負極集電体 １０・・・正極集電体 １１・・・負極リード １２・・・正極リード 1 ... Negative electrode 2 ... Positive electrode 3 ... Separator 4 ... Insulation plate 5 ... Battery can 6 ... Insulation sealing gasket 7 ... Battery lid 8 ... Safety valve device 9 ... Negative electrode current collector 10 ... Positive electrode current collector 11 ... Negative electrode lead 12 ... Positive electrode lead

─────────────────────────────────────────────────────
─────────────────────────────────────────────────── ───

【手続補正書】[Procedure amendment]

【提出日】平成６年３月２５日[Submission date] March 25, 1994

【手続補正１】[Procedure Amendment 1]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】００３２[Name of item to be corrected] 0032

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【００３２】ピッチとしては、コールタール、エチレン
ボトム油、原油等の高温熱分解で得られるタール類、ア
スファルトなどより蒸留（真空蒸留，常圧蒸留，スチー
ム蒸留）、熱重縮合、抽出、化学重縮合等の操作によっ
て得られるものや、その他木材乾留時に生成するピッチ
等が挙げられる。さらにピッチを生成する出発原料とし
ては、ポリ塩化ビニル樹脂、ポリビニルアセテート、ポ
リビニルブチラート、３，５−ジメチルフェノール樹脂
等の高分子化合物を出発原料とすることも可能である。As pitch, distillation (vacuum distillation, atmospheric distillation, steam distillation), thermal polycondensation, extraction, chemical polycondensation from coal tar, ethylene bottom oil, tars obtained by high temperature thermal decomposition of crude oil, asphalt, etc. Examples thereof include those obtained by operations such as condensation, and other pitches produced during carbonization of wood. Further, as a starting material for producing pitch, a polymer compound such as polyvinyl chloride resin, polyvinyl acetate, polyvinyl butyrate or 3,5-dimethylphenol resin can be used as a starting material.

【手続補正２】[Procedure Amendment 2]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】０１２４[Correction target item name] 0124

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【０１２４】[0124]

【表３】 [Table 3]

【手続補正３】[Procedure 3]

【補正対象書類名】明細書[Document name to be amended] Statement

【補正対象項目名】０１３４[Correction target item name] 0134

【補正方法】変更[Correction method] Change

【補正内容】[Correction content]

【０１３４】このことから、黒鉛としては、天然黒鉛で
あっても人造黒鉛であっても差し支えなく、充放電サイ
クル特性は黒鉛の電気化学的特性には依存するが黒鉛の
製法等には依らないことがわかる。From this, it is possible to use natural graphite or artificial graphite as the graphite. The charge / discharge cycle characteristics depend on the electrochemical characteristics of graphite but not on the graphite manufacturing method. I understand.

Claims (11)

【特許請求の範囲】[Claims] 【請求項１】 リチウムのドープ・脱ドープが可能な炭
素材料を負極材料とする負極と、リチウムを含む遷移金
属複合酸化物を正極活物質とする正極と、非水電解液を
具備してなる非水電解液二次電池において、 負極材料となる炭素材料は、難黒鉛化性炭素材料，易黒
鉛化性炭素材料の少なくともいずれかよりなる非黒鉛炭
素材料と、黒鉛の共存体であることを特徴とする非水電
解液二次電池。1. A negative electrode using a carbon material capable of doping / dedoping lithium as a negative electrode material, a positive electrode using a transition metal composite oxide containing lithium as a positive electrode active material, and a non-aqueous electrolytic solution. In the non-aqueous electrolyte secondary battery, the carbon material serving as the negative electrode material is a non-graphitizable carbon material composed of at least one of a non-graphitizable carbon material and a graphitizable carbon material, and a coexisting body of graphite. Characteristic non-aqueous electrolyte secondary battery. 【請求項２】 共存体のうち非黒鉛炭素材料は、断続充
放電法の１サイクル目で測定される１ｇ当たりの放電容
量が、黒鉛材料の断続充放電法の１サイクル目で測定さ
れる１ｇ当たりの放電容量の８０％以上であり、且つ非
黒鉛炭素材料の共存体全体に占める割合が１０〜９０重
量％であることを特徴とする請求項１記載の非水電解液
二次電池。2. The non-graphite carbon material among the coexisting substances has a discharge capacity per 1 g measured in the first cycle of the intermittent charge / discharge method, and a discharge capacity of 1 g measured in the first cycle of the intermittent charge / discharge method of the graphite material. 2. The non-aqueous electrolyte secondary battery according to claim 1, wherein the discharge capacity per unit is 80% or more, and the proportion of the non-graphite carbon material in the whole coexisting body is 10 to 90% by weight. 【請求項３】 非黒鉛炭素材料は、断続充放電法の１サ
イクル目で測定される放電容量において、リチウム電位
を基準電位としたときに、０．３Ｖまでの放電容量の
１．５Ｖまでの放電容量に対する比が０．５以上である
ことを特徴とする請求項２記載の非水電解液二次電池。3. The non-graphite carbon material has a discharge capacity measured in the first cycle of the intermittent charging / discharging method up to 0.3 V and a discharge capacity up to 1.5 V when the lithium potential is used as a reference potential. The non-aqueous electrolyte secondary battery according to claim 2, wherein the ratio to the discharge capacity is 0.5 or more. 【請求項４】 共存体のうち黒鉛は、真密度が２．１ｇ
／ｃｍ3 以上、Ｘ線回折法で求められる（００２）面の
面間隔が０．３４０ｎｍ未満、（００２）面のＣ軸結晶
子厚みが１４．０ｎｍ以上である請求項１記載の非水電
解液二次電池。4. The true density of graphite among the coexisting substances is 2.1 g.
/ Cm 3 or more, the interplanar spacing of the (002) plane determined by X-ray diffraction is less than 0.340 nm, and the C-axis crystallite thickness of the (002) plane is 14.0 nm or more. Liquid secondary battery. 【請求項５】 共存体のうち非黒鉛炭素材料は、真密度
が１．７０ｇ／ｃｍ3以下、Ｘ線回折法で求められる
（００２）面の面間隔が０．３７ｎｍ以上、空気気流中
での示差熱分析において７００℃以上に酸化発熱ピーク
が観測されない難黒鉛化性炭素であることを特徴とする
請求項１記載の非水電解液二次電池。5. The non-graphite carbon material among the coexisting substances has a true density of 1.70 g / cm 3 or less, a (002) plane spacing of 0.37 nm or more determined by an X-ray diffraction method, and an air flow. The non-aqueous electrolyte secondary battery according to claim 1, wherein the non-graphitizable carbon is a non-graphitizable carbon whose oxidation exothermic peak is not observed at 700 ° C. or higher in the differential thermal analysis. 【請求項６】 難黒鉛化性炭素材料は、リンを含有する
ことを特徴とする請求項５記載の非水電解液二次電池。6. The non-aqueous electrolyte secondary battery according to claim 5, wherein the non-graphitizable carbon material contains phosphorus. 【請求項７】 共存体は、難黒鉛化性炭素材料，易黒鉛
化性炭素材料の少なくともいずれかよりなる炭素材料、
または難黒鉛化性炭素材料あるいは易黒鉛化性炭素材料
の原料またはそれらの炭化前駆体に対して、周期率表の
ＩＶｂ〜ＶＩＩｂ及びＶＩＩＩ族元素からなる金属また
はその化合物を黒鉛化触媒として添加し、熱処理されて
生成される非黒鉛炭素材料と黒鉛材料の共存体である請
求項１記載の非水電解液二次電池。7. The coexisting body is a carbon material composed of at least one of a non-graphitizable carbon material and a graphitizable carbon material,
Alternatively, to a raw material of a non-graphitizable carbon material or an easily graphitizable carbon material or a carbonization precursor thereof, a metal or a compound thereof consisting of elements IVb to VIIb and VIII of the periodic table is added as a graphitization catalyst. The non-aqueous electrolyte secondary battery according to claim 1, which is a coexisting body of a non-graphite carbon material and a graphite material produced by heat treatment. 【請求項８】 非水電解液は、炭酸エチレンを含有する
非水溶媒に電解質が溶解されてなる電解液であることを
特徴とする請求項１記載の非水電解液二次電池。8. The non-aqueous electrolyte secondary battery according to claim 1, wherein the non-aqueous electrolyte is an electrolyte in which an electrolyte is dissolved in a non-aqueous solvent containing ethylene carbonate. 【請求項９】 非水溶媒は、鎖状炭酸エステルを含有す
ることを特徴とする請求項８記載の非水電解液二次電
池。9. The non-aqueous electrolyte secondary battery according to claim 8, wherein the non-aqueous solvent contains a chain carbonic acid ester. 【請求項１０】 鎖状炭酸エステルが非対称鎖状炭酸エ
ステルであることを特徴とする請求項９記載の非水電解
液二次電池。10. The non-aqueous electrolyte secondary battery according to claim 9, wherein the chain ester carbonate is an asymmetric chain ester carbonate. 【請求項１１】 鎖状炭酸エステルがメチルエチルカー
ボネートとジメチルカーボネートの混合溶媒であること
を特徴とする請求項９記載の非水電解液二次電池。11. The non-aqueous electrolyte secondary battery according to claim 9, wherein the chain ester carbonate is a mixed solvent of methyl ethyl carbonate and dimethyl carbonate.
JP03343494A 1993-06-03 1994-03-03 Non-aqueous electrolyte secondary battery Expired - Fee Related JP3430614B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP03343494A JP3430614B2 (en) 1993-06-03 1994-03-03 Non-aqueous electrolyte secondary battery

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
JP13334593 1993-06-03
JP5-290496 1993-11-19
JP5-133345 1993-11-19
JP29049693 1993-11-19
JP03343494A JP3430614B2 (en) 1993-06-03 1994-03-03 Non-aqueous electrolyte secondary battery

Publications (2)

Publication Number Publication Date
JPH07192724A true JPH07192724A (en) 1995-07-28
JP3430614B2 JP3430614B2 (en) 2003-07-28

Family

ID=27288070

Family Applications (1)

Application Number Title Priority Date Filing Date
JP03343494A Expired - Fee Related JP3430614B2 (en) 1993-06-03 1994-03-03 Non-aqueous electrolyte secondary battery

Country Status (1)

Country Link
JP (1) JP3430614B2 (en)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0776055A1 (en) 1995-11-24 1997-05-28 PETOCA, Ltd Negative electrode material for use in lithium-ion secondary battery and process for producing the same
JPH11246209A (en) * 1998-03-05 1999-09-14 Osaka Gas Co Ltd Negative electrode carbon material for lithium secondary cell and lithium secondary cell
JPH11265718A (en) * 1998-03-16 1999-09-28 Sanyo Electric Co Ltd Lithium secondary battery
WO2000013245A1 (en) * 1998-08-27 2000-03-09 Nec Corporation Nonaqueous electrolyte secondary cell, method for manufacturing the same, and carbonaceous material composition
JP2002008655A (en) * 2000-06-20 2002-01-11 Sony Corp Negative electrode and non-aqueous electrolyte cell
JP2002151157A (en) * 2000-11-13 2002-05-24 Japan Storage Battery Co Ltd Nonaqueous electrolyte secondary battery
JP2006318868A (en) * 2005-05-16 2006-11-24 Hitachi Maxell Ltd Lithium secondary battery
JP2007265831A (en) * 2006-03-29 2007-10-11 Gs Yuasa Corporation:Kk Nonaqueous electrolyte secondary battery
JP2009117240A (en) * 2007-11-08 2009-05-28 Osaka Gas Chem Kk Anode carbon material, and lithium secondary cell equipped with same
WO2010073931A1 (en) * 2008-12-26 2010-07-01 株式会社クレハ Method for producing negative electrode carbon material
US8158284B2 (en) * 2008-02-29 2012-04-17 Hitachi Vehicle Energy, Ltd. Lithium ion secondary battery
WO2013035859A1 (en) * 2011-09-09 2013-03-14 住友ベークライト株式会社 Carbon material for lithium ion secondary batteries, negative electrode material for lithium ion secondary batteries, and lithium ion secondary battery
JP2013058449A (en) * 2011-09-09 2013-03-28 Sumitomo Bakelite Co Ltd Carbon material for lithium ion secondary battery, negative electrode material for lithium ion secondary battery, and lithium ion secondary battery
WO2013051444A1 (en) * 2011-10-05 2013-04-11 住友ベークライト株式会社 Negative electrode for lithium ion secondary batteries, and lithium ion secondary battery
JP2013069556A (en) * 2011-09-22 2013-04-18 Sumitomo Bakelite Co Ltd Carbon material for lithium ion secondary battery, negative electrode material for lithium ion secondary battery, and lithium ion secondary battery
WO2015152092A1 (en) * 2014-03-31 2015-10-08 株式会社クレハ Negative-electrode material for nonaqueous-electrolyte secondary battery, negative-electrode mixture for nonaqueous-electrolyte secondary battery, negative electrode for nonaqueous-electrolyte secondary battery, nonaqueous-electrolyte secondary battery, and vehicle
JPWO2016076145A1 (en) * 2014-11-11 2017-08-17 株式会社Adeka Non-aqueous electrolyte secondary battery
JP2019091624A (en) * 2017-11-15 2019-06-13 トヨタ自動車株式会社 Method for manufacturing nonaqueous electrolyte secondary battery
WO2021132114A1 (en) 2019-12-24 2021-07-01 三洋電機株式会社 Negative electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery

Cited By (25)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0776055A1 (en) 1995-11-24 1997-05-28 PETOCA, Ltd Negative electrode material for use in lithium-ion secondary battery and process for producing the same
JPH11246209A (en) * 1998-03-05 1999-09-14 Osaka Gas Co Ltd Negative electrode carbon material for lithium secondary cell and lithium secondary cell
JPH11265718A (en) * 1998-03-16 1999-09-28 Sanyo Electric Co Ltd Lithium secondary battery
WO2000013245A1 (en) * 1998-08-27 2000-03-09 Nec Corporation Nonaqueous electrolyte secondary cell, method for manufacturing the same, and carbonaceous material composition
JP2002008655A (en) * 2000-06-20 2002-01-11 Sony Corp Negative electrode and non-aqueous electrolyte cell
JP2002151157A (en) * 2000-11-13 2002-05-24 Japan Storage Battery Co Ltd Nonaqueous electrolyte secondary battery
JP2006318868A (en) * 2005-05-16 2006-11-24 Hitachi Maxell Ltd Lithium secondary battery
JP2007265831A (en) * 2006-03-29 2007-10-11 Gs Yuasa Corporation:Kk Nonaqueous electrolyte secondary battery
JP2009117240A (en) * 2007-11-08 2009-05-28 Osaka Gas Chem Kk Anode carbon material, and lithium secondary cell equipped with same
JP4560076B2 (en) * 2007-11-08 2010-10-13 大阪ガスケミカル株式会社 Negative electrode carbon material and lithium secondary battery including the same
US8158284B2 (en) * 2008-02-29 2012-04-17 Hitachi Vehicle Energy, Ltd. Lithium ion secondary battery
JPWO2010073931A1 (en) * 2008-12-26 2012-06-14 株式会社クレハ Method for producing negative electrode carbon material
WO2010073931A1 (en) * 2008-12-26 2010-07-01 株式会社クレハ Method for producing negative electrode carbon material
JP5606926B2 (en) * 2008-12-26 2014-10-15 株式会社クレハ Method for producing negative electrode carbon material
US8470206B2 (en) 2008-12-26 2013-06-25 Kureha Corporation Method of producing anode material
US20140227522A1 (en) * 2011-09-09 2014-08-14 Sumitomo Bakelite Company Limited Carbon material for lithium ion secondary battery, negative electrode material for lithium ion secondary battery and lithium ion secondary battery
WO2013035859A1 (en) * 2011-09-09 2013-03-14 住友ベークライト株式会社 Carbon material for lithium ion secondary batteries, negative electrode material for lithium ion secondary batteries, and lithium ion secondary battery
JP2013058449A (en) * 2011-09-09 2013-03-28 Sumitomo Bakelite Co Ltd Carbon material for lithium ion secondary battery, negative electrode material for lithium ion secondary battery, and lithium ion secondary battery
JP2013069556A (en) * 2011-09-22 2013-04-18 Sumitomo Bakelite Co Ltd Carbon material for lithium ion secondary battery, negative electrode material for lithium ion secondary battery, and lithium ion secondary battery
WO2013051444A1 (en) * 2011-10-05 2013-04-11 住友ベークライト株式会社 Negative electrode for lithium ion secondary batteries, and lithium ion secondary battery
JP2013080659A (en) * 2011-10-05 2013-05-02 Sumitomo Bakelite Co Ltd Negative electrode for lithium ion secondary battery, and lithium ion secondary battery
WO2015152092A1 (en) * 2014-03-31 2015-10-08 株式会社クレハ Negative-electrode material for nonaqueous-electrolyte secondary battery, negative-electrode mixture for nonaqueous-electrolyte secondary battery, negative electrode for nonaqueous-electrolyte secondary battery, nonaqueous-electrolyte secondary battery, and vehicle
JPWO2016076145A1 (en) * 2014-11-11 2017-08-17 株式会社Adeka Non-aqueous electrolyte secondary battery
JP2019091624A (en) * 2017-11-15 2019-06-13 トヨタ自動車株式会社 Method for manufacturing nonaqueous electrolyte secondary battery
WO2021132114A1 (en) 2019-12-24 2021-07-01 三洋電機株式会社 Negative electrode for nonaqueous electrolyte secondary batteries, and nonaqueous electrolyte secondary battery

Also Published As

Publication number Publication date
JP3430614B2 (en) 2003-07-28

Similar Documents

Publication Publication Date Title
US5451477A (en) Non-aqueous liquid electrolyte secondary battery
JP3430614B2 (en) Non-aqueous electrolyte secondary battery
JP4228593B2 (en) Nonaqueous electrolyte secondary battery
JP3844495B2 (en) Non-aqueous electrolyte secondary battery
JP3436033B2 (en) Non-aqueous electrolyte secondary battery
JP2014099419A (en) Negative electrode and secondary battery
KR100418003B1 (en) Manufacturing method of carbonaceous material for negative electrode of battery and nonaqueous electrolyte secondary battery using same
JP3311104B2 (en) Lithium secondary battery
JPH09213335A (en) Lithium secondary cell
JP3709628B2 (en) Non-aqueous electrolyte secondary battery
US7658775B2 (en) Method for making negative electrode component including a carbonaceous material for use in a nonaqueous secondary battery
JP4150087B2 (en) Non-aqueous electrolyte secondary battery
JPH0927344A (en) Nonaqueous electrolyte secondary battery
JP3552377B2 (en) Rechargeable battery
JPH0613109A (en) Nonaqueous electrolyte secondary battery
WO1994014205A1 (en) Secondary cell of nonaqueous electrolyte
JPH07335262A (en) Nonaqueous electrolyte secondary battery
JP3430706B2 (en) Carbon material for negative electrode and non-aqueous electrolyte secondary battery
JPH08180873A (en) Manufacture of negative electrode material and nonaqueous electrolytic secondary battery
JP3787943B2 (en) Non-aqueous electrolyte secondary battery
JPH07320785A (en) Nonaqueous electrolytic secondary battery
JPS63114056A (en) Nonaqueous solvent secondary battery
JPH09283178A (en) Nonaqueous electrolyte secondary battery
JP2002164052A (en) Non-aqueous electrolytic battery
JP3718855B2 (en) Non-aqueous electrolyte secondary battery

Legal Events

Date Code Title Description
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20030422

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20080523

Year of fee payment: 5

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20090523

Year of fee payment: 6

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100523

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20100523

Year of fee payment: 7

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110523

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20110523

Year of fee payment: 8

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120523

Year of fee payment: 9

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20120523

Year of fee payment: 9

FPAY Renewal fee payment (event date is renewal date of database)

Free format text: PAYMENT UNTIL: 20130523

Year of fee payment: 10

LAPS Cancellation because of no payment of annual fees