JPH09320597A - Nonaqueous electrolytic battery - Google Patents
Nonaqueous electrolytic batteryInfo
- Publication number
- JPH09320597A JPH09320597A JP8156245A JP15624596A JPH09320597A JP H09320597 A JPH09320597 A JP H09320597A JP 8156245 A JP8156245 A JP 8156245A JP 15624596 A JP15624596 A JP 15624596A JP H09320597 A JPH09320597 A JP H09320597A
- Authority
- JP
- Japan
- Prior art keywords
- aqueous electrolyte
- graphitized carbon
- carbon
- negative electrode
- coating
- 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
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
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、正極と、炭素材
料を用いた負極と、非水電解液とを備えた非水電解質電
池に係り、炭素材料を用いた負極が改良されて保存特性
等が向上した非水電解質電池に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-aqueous electrolyte battery provided with a positive electrode, a negative electrode using a carbon material, and a non-aqueous electrolyte solution. The present invention relates to a non-aqueous electrolyte battery having improved characteristics.
【０００２】[0002]
【従来の技術】近年、高出力，高エネルギー密度の新型
電池の１つとして、電解質に非水電解液を用い、リチウ
ムの酸化，還元を利用した高起電力の非水電解質電池が
利用されるようになった。2. Description of the Related Art In recent years, a non-aqueous electrolyte battery having a high electromotive force using a non-aqueous electrolyte as an electrolyte and utilizing oxidation and reduction of lithium has been used as one of new batteries having a high output and a high energy density. It became so.
【０００３】そして、このような非水電解質電池におい
て、その負極材料として、従来よりリチウムイオンの吸
蔵，放出が可能な炭素材料が広く利用されていた。In such a non-aqueous electrolyte battery, a carbon material capable of inserting and extracting lithium ions has been widely used as a negative electrode material.
【０００４】ここで、このように負極に炭素材料を用い
た非水電解質電池の場合、保存時において負極の炭素材
料中に含まれるリチウムが非水電解液における溶媒等と
反応して自己放電し、次第に電池容量が低下するという
問題があった。Here, in the case of a non-aqueous electrolyte battery using a carbon material for the negative electrode, lithium contained in the carbon material of the negative electrode reacts with a solvent in the non-aqueous electrolytic solution during storage and self-discharges. However, there was a problem that the battery capacity gradually decreased.
【０００５】また、従来においては、上記のような非水
電解質電池において、特開平６−３０２３１５号公報に
示されるように、炭素材料等の活物質粉末に炭化ケイ素
ウィスカー，窒化ケイ素ウィスカー，チタン酸カリウム
ウィスカー等のウィスカーを混合させて、非水電解質電
池におけるサイクル保存特性を向上させるようにしたも
のや、特開平６−８４５１５号公報に示されるように、
負極に黒鉛とコークスとを混合させた炭素材料を用い、
これにより集電効率を向上させたもの等が開発されてい
る。Further, conventionally, in the above-mentioned non-aqueous electrolyte battery, as shown in JP-A-6-302315, silicon carbide whiskers, silicon nitride whiskers, titanic acid are added to active material powder such as carbon material. A mixture of whiskers such as potassium whiskers to improve cycle storage characteristics in a non-aqueous electrolyte battery, or as disclosed in JP-A-6-84515,
Using a carbon material in which graphite and coke are mixed in the negative electrode,
As a result, products having improved current collection efficiency have been developed.
【０００６】しかし、これらの公報に示されるものにお
いても、上記のように負極に用いた炭素材料中における
リチウムが非水電解液における溶媒等と反応して自己放
電が生じるのを十分に抑制することはできず、依然とし
て保存時に電池容量が低下するという問題があった。However, even in those disclosed in these publications, the lithium in the carbon material used for the negative electrode is sufficiently suppressed from reacting with the solvent or the like in the non-aqueous electrolyte to cause self-discharge as described above. However, there is still a problem that the battery capacity decreases during storage.
【０００７】[0007]
【発明が解決しようとする課題】この発明は、正極と、
炭素材料を用いた負極と、非水電解質とを備えた非水電
解質電池における上記のような問題を解決することを課
題とするものであり、保存時に負極に用いた炭素材料中
におけるリチウムが非水電解液における溶媒等と反応し
て自己放電が生じるのを抑制し、保存特性の良い非水電
解質電池が得られるようにすることを課題とするもので
ある。SUMMARY OF THE INVENTION The present invention provides a positive electrode,
An object is to solve the above problems in a non-aqueous electrolyte battery including a negative electrode using a carbon material and a non-aqueous electrolyte, and lithium in the carbon material used in the negative electrode during storage is non- It is an object of the present invention to suppress self-discharge due to reaction with a solvent or the like in an aqueous electrolytic solution and to obtain a non-aqueous electrolyte battery having good storage characteristics.
【０００８】[0008]
【課題を解決するための手段】この発明における非水電
解質電池においては、上記のような課題を解決するため
に、正極と、炭素材料を用いた負極と、非水電解液とを
備えた非水電解質電池において、負極における炭素材料
として、格子面（００２）面における面間隔（ｄ002 ）
が３．３５〜３．３９Åの範囲でありかつｃ軸方向の結
晶子の大きさ（Ｌｃ）が１０００Å以上である核となる
黒鉛化炭素を、格子面（００２）面における面間隔（ｄ
002 ）が３．３６〜３．４８Åの範囲で上記の核となる
黒鉛化炭素における面間隔（ｄ002 ）以上の大きさにな
った被覆用黒鉛化炭素で被覆したものを用いるようにし
たのである。In order to solve the above problems, a non-aqueous electrolyte battery according to the present invention includes a non-aqueous electrolyte battery including a positive electrode, a negative electrode using a carbon material, and a non-aqueous electrolyte solution. In the water electrolyte battery, as the carbon material for the negative electrode, the lattice spacing (d 002 ) on the lattice plane (002) plane is used.
Is in the range of 3.35 to 3.39Å and the crystallite size (Lc) in the c-axis direction is 1000Å or more.
002 ) is in the range of 3.36 to 3.48 Å, and the graphitized carbon coated as the core has a size larger than the interplanar spacing (d 002 ) of the graphitized carbon. is there.
【０００９】そして、この発明における非水電解質電池
のように、負極における炭素材料として、上記の核とな
る黒鉛化炭素を上記の被覆用黒鉛化炭素で被覆したもの
を用いると、この被覆用黒鉛化炭素により核となる黒鉛
化炭素中におけるリチウムが保存時において非電解液に
おける溶媒等と反応して自己放電が生じるのが抑制さ
れ、保存時において電池容量が低下するということが少
なく、非水電解質電池における保存特性が向上する。As in the non-aqueous electrolyte battery according to the present invention, when the carbon material for the above-mentioned core, graphitized carbon, is coated with the above-mentioned graphitized carbon for coating, the graphite for coating is used. It is suppressed that lithium in graphitized carbon, which becomes a nucleus by carbonized carbon, reacts with the solvent in the non-electrolyte during storage to cause self-discharge, and the battery capacity is less likely to decrease during storage. The storage characteristics of the electrolyte battery are improved.
【００１０】ここで、この発明における非水電解質電池
において、核となる黒鉛化炭素として、格子面（００
２）面における面間隔（ｄ002 ）が３．３５〜３．３９
Åでかつｃ軸方向の結晶子の大きさ（Ｌｃ）が１０００
Å以上の黒鉛化炭素を用いるようにしたのは、このよう
な黒鉛化炭素は結晶性が高く、リチウムイオンの吸蔵，
放出が十分に行なわれ、高容量の電池が得られるように
なるためであり、このような黒鉛化炭素としては、一般
に天然黒鉛が用いられる。Here, in the non-aqueous electrolyte battery according to the present invention, the lattice plane (00
2) The surface spacing (d 002 ) in the plane is 3.35 to 3.39.
Å and the crystallite size (Lc) in the c-axis direction is 1000
Å The above graphitized carbon is used because such graphitized carbon has high crystallinity and can absorb lithium ions,
This is because the carbon dioxide is sufficiently discharged and a high-capacity battery can be obtained. As such graphitized carbon, natural graphite is generally used.
【００１１】一方、このような核となる黒鉛化炭素を被
覆する被覆用黒鉛化炭素として、格子面（００２）面に
おける面間隔（ｄ002 ）が３．３６〜３．４８Åの範囲
でかつ核となる黒鉛化炭素における面間隔（ｄ002 ）以
上の大きさになった黒鉛化炭素を用いるようにしたの
は、核となる黒鉛化炭素中におけるリチウムが非水電解
液における溶媒等と反応するのを十分に抑制するためで
あり、この被覆用黒鉛化炭素には一般に人造黒鉛が用い
られる。On the other hand, as the graphitized carbon for coating which coats such cored graphitized carbon, the interplanar spacing (d 002 ) in the lattice plane (002) plane is in the range of 3.36 to 3.48Å and the core is The graphitized carbon having a size larger than the interplanar spacing (d 002 ) in the graphitized carbon as the core is used because lithium in the core graphitized carbon reacts with a solvent or the like in the non-aqueous electrolyte solution. The artificial graphite is generally used for the graphitized carbon for coating.
【００１２】そして、この被覆用黒鉛化炭素によって上
記の核となる黒鉛化炭素を被覆するにあたり、この被覆
用黒鉛化炭素の量が少ないと、核となる黒鉛化炭素を十
分に被覆することができず、核となる黒鉛化炭素に含ま
れたリチウムが非水電解液の溶媒等と反応するのを十分
に抑制することができなくなる一方、その量が多くなり
すぎると、核となる黒鉛化炭素の量が少なくなって、負
極におけるリチウムイオンの吸蔵，放出性能が低下する
ため、黒鉛化炭素全体の量に対して、この被覆用黒鉛化
炭素の量を０．１〜６０重量％、好ましくは１〜５０重
量％、より好ましくは１０〜３０重量％の範囲になるよ
うにする。In coating the core graphitized carbon with the coating graphitized carbon, when the amount of the coating graphitized carbon is small, the core graphitized carbon can be sufficiently coated. It is not possible to sufficiently suppress the reaction of the lithium contained in the graphitized carbon, which becomes the core, with the solvent of the non-aqueous electrolyte, while if the amount becomes too large, the graphitization that becomes the core Since the amount of carbon becomes small and the occlusion and release performance of lithium ions in the negative electrode deteriorates, the amount of the graphitized carbon for coating is preferably 0.1 to 60% by weight, preferably the amount of the graphitized carbon for coating. Is 1 to 50% by weight, more preferably 10 to 30% by weight.
【００１３】また、この発明における非水電解質電池に
おいて、その正極に使用する正極材料としては、従来よ
り使用されている公知の正極材料を用いることができ、
リチウムイオンを吸蔵，放出できる材料として、例え
ば、マンガン，コバルト，ニッケル，鉄，バナジウム，
ニオブの少なくとも１種を含むリチウム遷移金属複合酸
化物等を使用することができ、より具体的には、ＬｉＣ
ｏＯ2 、ＬｉＮｉＯ2 、ＬｉＭｎＯ2 、ＬｉＦｅＯ2 等
の材料を使用することができる。In the non-aqueous electrolyte battery according to the present invention, as the positive electrode material used for the positive electrode, a known positive electrode material which has been conventionally used can be used.
Materials capable of absorbing and releasing lithium ions include, for example, manganese, cobalt, nickel, iron, vanadium,
For example, a lithium transition metal composite oxide containing at least one niobium can be used, and more specifically, LiC
oO 2, LiNiO 2, LiMnO 2 , it is possible to use a material such as LiFeO 2.
【００１４】また、この発明の非水電解質電池における
非水電解液としては、従来より使用されている公知の非
水電解液を用いることができる。As the non-aqueous electrolytic solution in the non-aqueous electrolyte battery of the present invention, a known non-aqueous electrolytic solution which has been conventionally used can be used.
【００１５】そして、この非水電解液における溶媒とし
ては、例えば、エチレンカーボネート、プロピレンカー
ボネート、ブチレンカーボネート、ビニレンカーボネー
ト、シクロペンタノン、スルホラン、ジメチルスルホラ
ン、３−メチル−１，３−オキサゾリジン−２−オン、
γ−ブチロラクトン、ジメチルカーボネート、ジエチル
カーボネート、エチルメチルカーボネート、メチルプロ
ピルカーボネート、ブチルメチルカーボネート、エチル
プロピルカーボネート、ブチスエチルカーボネート、ジ
プロピルカーボネート、１，２−ジメトキシエタン、テ
トラヒドロフラン、２−メチルテトラヒドロフラン、
１，３−ジオキソラン、酢酸メチル、酢酸エチル等の有
機溶媒を１種又は２種以上組み合わせて使用することが
できる。As the solvent in the non-aqueous electrolyte, for example, ethylene carbonate, propylene carbonate, butylene carbonate, vinylene carbonate, cyclopentanone, sulfolane, dimethyl sulfolane, 3-methyl-1,3-oxazolidin-2-yl on,
γ-butyrolactone, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, methyl propyl carbonate, butyl methyl carbonate, ethyl propyl carbonate, butisethyl carbonate, dipropyl carbonate, 1,2-dimethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran,
Organic solvents such as 1,3-dioxolan, methyl acetate and ethyl acetate can be used alone or in combination of two or more.
【００１６】また、この非水電解液において上記のよう
な溶媒に溶解させる溶質としては、例えば、ＬｉＰＦ
6 、ＬｉＢＦ4 、ＬｉＣｌＯ4 、ＬｉＣＦ3 ＳＯ3 、Ｌ
ｉＡｓＦ6 、ＬｉＮ（ＣＦ3 ＳＯ2 ）2 、ＬｉＯＳＯ2
（ＣＦ2 ）3 ＣＦ3 等のリチウム化合物を使用すること
ができる。The solute to be dissolved in the above-mentioned solvent in this non-aqueous electrolyte is, for example, LiPF.
6 , LiBF 4 , LiClO 4 , LiCF 3 SO 3 , L
iAsF 6 , LiN (CF 3 SO 2 ) 2 , LiOSO 2
Lithium compounds such as (CF 2 ) 3 CF 3 can be used.
【００１７】[0017]
【実施例】以下、この発明に係る非水電解質電池につい
て、実施例を挙げて具体的に説明すると共に、この発明
の実施例に係る非水電解質電池が保存特性等の点で優れ
ていることを比較例を挙げて明らかにする。なお、この
発明における非水電解質電池は、下記の実施例に示した
ものに限定されるものではなく、その要旨を変更しない
範囲において適宜変更して実施できるものである。EXAMPLES Hereinafter, the nonaqueous electrolyte battery according to the present invention will be specifically described with reference to examples, and the nonaqueous electrolyte battery according to the examples of the present invention will be excellent in storage characteristics and the like. Will be clarified with reference to comparative examples. The non-aqueous electrolyte battery according to the present invention is not limited to the ones shown in the following examples, and can be implemented with appropriate modifications without departing from the scope of the invention.
【００１８】（実施例１）この実施例における非水電解
質電池においては、下記のようにして作製した正極と負
極とを用いると共に、下記のようにして調製した非水電
解液を用い、図１に示すような円筒型の非水電解質二次
電池を作製した。(Example 1) In the non-aqueous electrolyte battery in this example, the positive electrode and the negative electrode prepared as described below were used, and the non-aqueous electrolyte solution prepared as described below was used. A cylindrical non-aqueous electrolyte secondary battery as shown in was produced.
【００１９】［正極の作製］正極を作製するにあたって
は、正極材料として、８００℃で熱処理したリチウム含
有二酸化コバルトＬｉＣｏＯ2 を用いるようにした。な
お、熱処理の温度は７００〜９００℃の範囲で行なうこ
とができる。[Preparation of Positive Electrode] In preparing the positive electrode, lithium-containing cobalt dioxide LiCoO 2 heat-treated at 800 ° C. was used as the positive electrode material. The heat treatment temperature may be 700 to 900 ° C.
【００２０】そして、この正極材料ＬｉＣｏＯ2 と、導
電剤であるカーボン粉末と、結着剤であるフッ素樹脂粉
末とを８５：１０：５の重量比で混合し、この混合物を
正極集電体のアルミニウム箔に塗布した後、１５０℃で
熱処理して正極を作製した。なお、この熱処理の温度は
１００〜２００℃の範囲で行なうことができる。Then, the positive electrode material LiCoO 2 , carbon powder as a conductive agent, and fluororesin powder as a binder were mixed in a weight ratio of 85: 10: 5, and this mixture was mixed into a positive electrode current collector. After applying on an aluminum foil, it was heat-treated at 150 ° C. to prepare a positive electrode. The temperature of this heat treatment can be performed in the range of 100 to 200 ° C.
【００２１】［負極の作製］負極を作製するにあたって
は、負極材料として、格子面（００２）面における面間
隔ｄ002 が３．３６Åでｃ軸方向の結晶子の大きさＬｃ
が２１００Åの核となる黒鉛化炭素に、格子面（００
２）面における面間隔ｄ002 が３．４０Åの被覆用黒鉛
化炭素を黒鉛化炭素の全体の２０重量％になるように被
覆させたものを用い、この負極材料と結着剤であるポリ
フッ化ビニリデンとを９５：５の重量比で混合し、この
混合物を銅箔からなる負極集電体に塗布した後、これを
２００℃で熱処理して負極を作製した。なお、この熱処
理は１５０〜２５０℃の範囲で行なうことができる。[Manufacture of Negative Electrode] When manufacturing a negative electrode, as a negative electrode material, the interplanar spacing d 002 in the lattice plane (002) plane is 3.36Å, and the crystallite size Lc in the c-axis direction is Lc.
On the graphitized carbon that becomes the nucleus of 2100Å,
2) A negative electrode material and polyfluoride as a binder were prepared by using coating graphitized carbon having a surface spacing d 002 of 3.40 Å so as to be 20% by weight of the whole graphitized carbon. Vinylidene was mixed in a weight ratio of 95: 5, the mixture was applied to a negative electrode current collector made of copper foil, and then this was heat-treated at 200 ° C. to prepare a negative electrode. This heat treatment can be performed within the range of 150 to 250 ° C.
【００２２】［非水電解液の調製］非水電解液を調製す
るにあたっては、エチレンカーボネートと１，２−ジメ
トキシエタンとを１：１の体積比で混合させた混合溶媒
を用い、この混合溶媒に溶質としてヘキサフルオロリン
酸リチウムＬｉＰＦ6 を１ｍｏｌ／ｌの割合で溶解させ
て非水電解液を調製した。[Preparation of Non-Aqueous Electrolyte] In preparing the non-aqueous electrolyte, a mixed solvent prepared by mixing ethylene carbonate and 1,2-dimethoxyethane at a volume ratio of 1: 1 was used. A non-aqueous electrolyte was prepared by dissolving lithium hexafluorophosphate LiPF 6 as a solute at a ratio of 1 mol / l.
【００２３】［電池の作製］そして、この実施例の非水
電解質二次電池を作製するにあたっては、図１に示すよ
うに、上記のようにして作製した正極１と負極２との間
にそれぞれセパレータ３としてリチウムイオン透過性の
ポリプロピレン製の微多孔膜を介在させ、これらをスパ
イラル状に巻いて電池缶４内に収容させた後、この電池
缶４内に上記の非水電解液を注液して封口し、正極１を
正極リード５を介して正極外部端子６に接続させると共
に負極２を負極リード７を介して電池缶４に接続させ、
電池缶４と正極外部端子６とを絶縁パッキン８により電
気的に分離させた。[Production of Battery] Then, in producing the non-aqueous electrolyte secondary battery of this example, as shown in FIG. 1, the positive electrode 1 and the negative electrode 2 produced as described above were respectively separated. A lithium ion-permeable polypropylene microporous film is interposed as a separator 3, and these are spirally wound to be housed in a battery can 4, and then the above nonaqueous electrolytic solution is injected into the battery can 4. Then, the positive electrode 1 is connected to the positive electrode external terminal 6 via the positive electrode lead 5, and the negative electrode 2 is connected to the battery can 4 via the negative electrode lead 7.
The battery can 4 and the positive electrode external terminal 6 were electrically separated by the insulating packing 8.
【００２４】（比較例１〜４）これらの比較例において
は、実施例１の非水電解質二次電池における負極の作製
において、使用する負極材料だけを変更させ、それ以外
については、実施例１の場合と同様にして非水電解質二
次電池を作製した。(Comparative Examples 1 to 4) In these Comparative Examples, only the negative electrode material used was changed in the production of the negative electrode in the non-aqueous electrolyte secondary battery of Example 1, and other than that, Example 1 was used. A non-aqueous electrolyte secondary battery was produced in the same manner as in the above.
【００２５】ここで、比較例１においては、その負極材
料として、上記の実施例１において使用した核となる黒
鉛化炭素だけを用いるようにし、また比較例２において
は、上記の核となる黒鉛化炭素に対して窒化ケイ素ウィ
スカーを２０重量％被覆させたものを用いるようにし、
比較例３においては、上記の核となる黒鉛化炭素に対し
て格子面（００２）面における面間隔ｄ002 が３．４６
〜３．４８Åでかつｃ軸方向の結晶子の大きさＬｃが１
５〜２０Åのコークスを２０重量％被覆させたものを用
いるようにし、比較例４においては、上記の核となる黒
鉛化炭素に対して３，５−ジメチルフェノールホルムア
ルデヒド樹脂炭からなる無定形炭素を２０重量％被覆さ
せたものを用いるようにした。Here, in Comparative Example 1, only the graphitized carbon serving as the core used in Example 1 was used as the negative electrode material, and in Comparative Example 2, the graphite serving as the core was used. 20% by weight of silicon nitride whiskers coated on carbon oxide should be used.
In Comparative Example 3, the interplanar spacing d 002 in the lattice plane (002) plane was 3.46 with respect to the graphitized carbon serving as the nucleus.
Up to 3.48Å and the crystallite size Lc in the c-axis direction is 1
A 20% by weight coating of 5 to 20Å of coke was used, and in Comparative Example 4, amorphous carbon composed of 3,5-dimethylphenolformaldehyde resin carbon was added to the graphitized carbon serving as the core. A coating with 20% by weight was used.
【００２６】そして、上記のようにして作製した実施例
１及び比較例１〜４の各非水電解質二次電池について、
保存前と６０℃で２ヶ月間保存した後とにおいて、それ
ぞれ放電電流２００ｍＡで放電終止電圧２．７５Ｖまで
放電させて、保存前と保存後における放電容量を測定
し、上記のように２ヶ月間保存した場合における各非水
電解質二次電池の自己放電率（％）を求め、その結果を
下記の表１に示した。Then, with respect to the non-aqueous electrolyte secondary batteries of Example 1 and Comparative Examples 1 to 4 produced as described above,
Before storage and after storage at 60 ° C for 2 months, the discharge capacity was measured before and after storage by discharging at a discharge current of 200 mA to a discharge end voltage of 2.75 V, respectively, and storing for 2 months as described above. The self-discharge rate (%) of each non-aqueous electrolyte secondary battery when stored was determined, and the results are shown in Table 1 below.
【００２７】[0027]
【表１】 [Table 1]
【００２８】この結果、上記のような核となる黒鉛化炭
素を上記の被覆用黒鉛化炭素で被覆した実施例１の非水
電解質二次電池は、核となる黒鉛化炭素を被覆しなかっ
た比較例１の非水電解質二次電池や、核となる黒鉛化炭
素を窒化ケイ素ウィスカーやコークスや３，５−ジメチ
ルフェノールホルムアルデヒド樹脂炭で被覆した比較例
２〜４の非水電解質二次電池に比べて自己放電率が低く
なっていた。As a result, the non-aqueous electrolyte secondary battery of Example 1 in which the above graphitized carbon serving as the core was coated with the above graphitized carbon for coating, did not cover the graphitized carbon serving as the core. The non-aqueous electrolyte secondary battery of Comparative Example 1 and the non-aqueous electrolyte secondary batteries of Comparative Examples 2 to 4 in which the graphitized carbon serving as the core was coated with silicon nitride whiskers, coke or 3,5-dimethylphenolformaldehyde resin charcoal Compared with this, the self-discharge rate was low.
【００２９】（実施例２）この実施例においては、実施
例１の非水電解質二次電池における非水電解液の調製に
おいて、溶媒としてプロピレンカーボネートと１，２−
ジメトキシエタンとを１：１の体積比で混合させた混合
溶媒を用いるようにし、それ以外については、上記実施
例１の場合と同様にして非水電解質二次電池を作製し
た。(Example 2) In this example, in the preparation of the non-aqueous electrolyte in the non-aqueous electrolyte secondary battery of Example 1, propylene carbonate and 1,2-
A non-aqueous electrolyte secondary battery was produced in the same manner as in Example 1 except that a mixed solvent obtained by mixing dimethoxyethane at a volume ratio of 1: 1 was used.
【００３０】（比較例５〜８）これらの比較例において
は、非水電解液における溶媒として、上記の実施例２と
同様にプロピレンカーボネートと１，２−ジメトキシエ
タンとを１：１の体積比で混合させた混合溶媒を用いる
ようにし、また負極材料として、比較例５では上記の比
較例１と同様に核となる黒鉛化炭素だけを、比較例６で
は上記の比較例２と同様に核となる黒鉛化炭素を窒化ケ
イ素ウィスカーで被覆したものを、比較例７では上記の
比較例３と同様に核となる黒鉛化炭素をコークスで被覆
したものを、比較例８では上記の比較例４と同様に核と
なる黒鉛化炭素を３，５−ジメチルフェノールホルムア
ルデヒド樹脂炭で被覆したものを用い、それ以外につい
ては、上記実施例１の場合と同様にして非水電解質二次
電池を作製した。(Comparative Examples 5 to 8) In these Comparative Examples, propylene carbonate and 1,2-dimethoxyethane were used as the solvent in the non-aqueous electrolytic solution in the same volume ratio of 1: 1 as in Example 2 above. In Comparative Example 5, only the graphitized carbon that serves as the core in Comparative Example 5 is used as the negative electrode material, and in Comparative Example 6, the core is prepared as in Comparative Example 2 described above. The graphitized carbon which becomes the following is coated with silicon nitride whiskers, the graphitized carbon serving as the core is coated with coke in the same manner as in the above-mentioned Comparative Example 3 in Comparative Example 7, and the above Comparative Example 4 is described in Comparative Example 8. A non-aqueous electrolyte secondary battery was prepared in the same manner as in Example 1 except that the core graphitized carbon was coated with 3,5-dimethylphenolformaldehyde resin charcoal in the same manner as in. .
【００３１】そして、上記のようにして作製した実施例
２及び比較例５〜８の各非水電解質二次電池について
も、前記の場合と同様にして、保存前と６０℃で２ヶ月
間保存した後とにおける放電容量を測定し、２ヶ月間保
存した場合における各非水電解質二次電池の自己放電率
（％）を求め、その結果を下記の表２に示した。The non-aqueous electrolyte secondary batteries of Example 2 and Comparative Examples 5 to 8 produced as described above were also stored in the same manner as above before storage and at 60 ° C. for 2 months. After that, the discharge capacity was measured, and the self-discharge rate (%) of each non-aqueous electrolyte secondary battery when stored for 2 months was determined. The results are shown in Table 2 below.
【００３２】[0032]
【表２】 [Table 2]
【００３３】この結果、非水電解液に使用する溶媒の種
類を変更させた場合であっても、上記実施例１及び比較
例１〜４の場合と同様に、上記のような核となる黒鉛化
炭素を上記の被覆用黒鉛化炭素で被覆した実施例２の非
水電解質二次電池は、比較例５〜８の各非水電解質二次
電池に比べて自己放電率が低くなっていた。As a result, even when the type of the solvent used in the non-aqueous electrolyte solution is changed, the core graphite as described above is used as in the case of Example 1 and Comparative Examples 1 to 4. The nonaqueous electrolyte secondary battery of Example 2 in which the carbonized carbon was coated with the above-mentioned graphitized carbon for coating had a lower self-discharge rate than the nonaqueous electrolyte secondary batteries of Comparative Examples 5 to 8.
【００３４】（実験例１）この実験例においては、実施
例１の非水電解質二次電池における負極の作製におい
て、前記の核となる黒鉛化炭素を前記の被覆用黒鉛化炭
素で被覆するあたり、被覆用黒鉛化炭素の全体の黒鉛化
炭素に対する被覆量を、下記の表３に示すように０〜７
０重量％の範囲で変更させて、各非水電解質二次電池を
作製した。(Experimental Example 1) In this experimental example, in the production of the negative electrode in the non-aqueous electrolyte secondary battery of Example 1, the core of the graphitized carbon was coated with the coating graphitized carbon. The coating amount of the graphitized carbon for coating with respect to the entire graphitized carbon is 0 to 7 as shown in Table 3 below.
Each nonaqueous electrolyte secondary battery was manufactured by changing the content within the range of 0% by weight.
【００３５】そして、これらの各非水電解質二次電池を
それぞれ６０℃で２ヶ月間保存した後、前記のように放
電電流２００ｍＡで放電終止電圧２．７５Ｖまで放電さ
せて、保存後における各非水電解質二次電池の放電容量
を調べ、その結果を下記の表３及び図２に示した。な
お、これらの各非水電解質二次電池における保存前の放
電容量は６００ｍＡｈであった。Then, each of these non-aqueous electrolyte secondary batteries was stored at 60 ° C. for 2 months, and then discharged to a discharge end voltage of 2.75 V at a discharge current of 200 mA as described above to store each non-aqueous electrolyte secondary battery. The discharge capacity of the water electrolyte secondary battery was investigated, and the results are shown in Table 3 and FIG. 2 below. The discharge capacity before storage in each of these non-aqueous electrolyte secondary batteries was 600 mAh.
【００３６】[0036]
【表３】 [Table 3]
【００３７】この結果、上記のような核となる黒鉛化炭
素を上記の被覆用黒鉛化炭素で被覆した非水電解質二次
電池は、核となる黒鉛化炭素を被覆しなかったものに対
して保存後における放電容量が著しく向上していた。ま
た、核となる黒鉛化炭素を被覆用黒鉛化炭素で被覆する
場合、その被覆量が全黒鉛化炭素の量に対して０．１〜
６０重量％の範囲、好ましくは１〜５０重量％の範囲、
より好ましくは１０〜３０重量％の範囲において、保存
後における放電容量の低下が少なくなり、保存特性に優
れた非水電解質二次電池が得られた。As a result, the non-aqueous electrolyte secondary battery prepared by coating the above-mentioned graphitized carbon serving as the core with the above-mentioned graphitized carbon for coating was prepared in comparison with the one not coated with the graphitized carbon serving as the core. The discharge capacity after storage was significantly improved. When the graphitized carbon serving as the core is coated with the graphitized carbon for coating, the coating amount is 0.1 to the total amount of graphitized carbon.
In the range of 60% by weight, preferably in the range of 1 to 50% by weight,
More preferably, in the range of 10 to 30% by weight, the decrease in discharge capacity after storage was reduced, and a non-aqueous electrolyte secondary battery having excellent storage characteristics was obtained.
【００３８】（実験例２）この実験例においては、実施
例１の非水電解質二次電池における負極の作製におい
て、上記の核となる黒鉛化炭素を被覆用黒鉛化炭素によ
って被覆するにあたり、この被覆用黒鉛化炭素として、
格子面（００２）面における面間隔ｄ002 が下記の表４
に示すように３．３６〜３．４９Åの範囲になった各被
覆用黒鉛化炭素を用いて各非水電解質二次電池を作製し
た。(Experimental Example 2) In this experimental example, when the graphitized carbon serving as the core was coated with the graphitized carbon for coating in the preparation of the negative electrode in the non-aqueous electrolyte secondary battery of Example 1, As graphitized carbon for coating,
The surface spacing d 002 in the lattice plane (002) plane is shown in Table 4 below.
Each non-aqueous electrolyte secondary battery was produced by using each coating graphitized carbon in the range of 3.36 to 3.49Å as shown in FIG.
【００３９】そして、これらの各非水電解質二次電池に
ついても、上記の実験例１の場合と同様にして、６０℃
で２ヶ月間保存させた後における各非水電解質電池の放
電容量を調べ、その結果を下記の表４及び図３に示し
た。なお、これらの各非水電解質二次電池における保存
前の放電容量は６００ｍＡｈであった。Then, with respect to each of these non-aqueous electrolyte secondary batteries, in the same manner as in the above-mentioned Experimental Example 1, 60 ° C.
The storage capacity of each non-aqueous electrolyte battery after storage for 2 months was examined, and the results are shown in Table 4 and FIG. 3 below. The discharge capacity before storage in each of these non-aqueous electrolyte secondary batteries was 600 mAh.
【００４０】[0040]
【表４】 [Table 4]
【００４１】この結果、上記のように格子面（００２）
面における面間隔ｄ002 が３．３６Åになった核となる
黒鉛化炭素を被覆用黒鉛化炭素によって被覆するにあた
り、格子面（００２）面における面間隔ｄ002 が３．３
６〜３．４９Åの範囲で、その面間隔ｄ002 が核となる
黒鉛化炭素における面間隔ｄ002 以上の大きさになった
被覆用黒鉛化炭素によって被覆すると、核となる黒鉛化
炭素を被覆しなかったものに対して保存後における放電
容量が著しく向上していた。As a result, as described above, the lattice plane (002)
When the graphitized carbon that serves as the core having the interplanar spacing d 002 of 3.36 Å is coated with the coating graphitized carbon, the interplanar spacing d 002 of the lattice plane (002) plane is 3.3.
In the range of 6 to 3.49Å, when the interplanar spacing d 002 is covered with the graphitizing carbon for coating whose interplanar spacing d 002 is larger than the interplanar spacing d 002 , the core graphitized carbon is coated. The discharge capacity after storage was remarkably improved as compared with the case of not performing.
【００４２】[0042]
【発明の効果】以上詳述したように、この発明における
非水電解質電池においては、負極における炭素材料とし
て、前記の核となる黒鉛化炭素を前記の被覆用黒鉛化炭
素で被覆したものを用いたため、保存時において核とな
る黒鉛化炭素の末端中に含まれるリチウムが非水電解液
の溶媒等と接触して反応するのが被覆用黒鉛化炭素によ
って抑制され、これにより非水電解質電池における自己
放電が抑制されて、保存特性に優れた非水電解質電池が
得られるようになった。As described above in detail, in the non-aqueous electrolyte battery of the present invention, the carbon material of the negative electrode is formed by coating the above-mentioned graphitized carbon serving as the core with the above-mentioned graphitized carbon for coating. Therefore, the lithium contained in the ends of the graphitized carbon serving as the core during storage is suppressed by the coating graphitized carbon from reacting with the solvent of the non-aqueous electrolytic solution and the like, whereby the non-aqueous electrolyte battery By suppressing self-discharge, a non-aqueous electrolyte battery having excellent storage characteristics can be obtained.
【図１】この発明の実施例及び比較例における非水電解
質電池の内部構造を示した断面説明図である。FIG. 1 is a cross-sectional explanatory view showing an internal structure of a non-aqueous electrolyte battery in Examples and Comparative Examples of the present invention.
【図２】実験例１において、核となる黒鉛化炭素を被覆
する被覆用黒鉛化炭素の被覆量と保存後の放電容量との
関係を示した図である。FIG. 2 is a diagram showing the relationship between the coating amount of the graphitized carbon for coating that covers the graphitized carbon serving as the core and the discharge capacity after storage in Experimental Example 1.
【図３】実験例２において、核となる黒鉛化炭素を被覆
する被覆用黒鉛化炭素の格子面（００２）面における面
間隔ｄ002 の大きさと保存後の放電容量との関係を示し
た図である。FIG. 3 is a diagram showing the relationship between the size of the interplanar spacing d 002 on the lattice plane (002) plane of the graphitized carbon for coating that covers the graphitized carbon serving as the core and the discharge capacity after storage in Experimental Example 2. Is.
１ 正極 ２ 負極 1 Positive electrode 2 Negative electrode
───────────────────────────────────────────────────── フロントページの続き (72)発明者 西尾 晃治 大阪府守口市京阪本通２丁目５番５号 三 洋電機株式会社内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Koji Nishio 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.
Claims (2)
電解液とを備えた非水電解質電池において、負極におけ
る炭素材料として、格子面（００２）面における面間隔
（ｄ002 ）が３．３５〜３．３９Åの範囲でありかつｃ
軸方向の結晶子の大きさ（Ｌｃ）が１０００Å以上であ
る核となる黒鉛化炭素を、格子面（００２）面における
面間隔（ｄ002 ）が３．３６〜３．４８Åの範囲で上記
の核となる黒鉛化炭素における面間隔（ｄ002 ）以上の
大きさになった被覆用黒鉛化炭素で被覆したものを用い
たことを特徴とする非水電解質電池。1. A non-aqueous electrolyte battery comprising a positive electrode, a negative electrode using a carbon material, and a non-aqueous electrolyte, wherein the carbon material in the negative electrode has a lattice spacing (d 002 ) on a lattice plane (002) plane. 3.35 to 3.39Å and c
The graphitized carbon serving as a nucleus having a crystallite size (Lc) in the axial direction of 1000 Å or more is used in the above-mentioned manner with the lattice spacing (d 002 ) in the lattice plane (002) plane being in the range of 3.36 to 3.48 Å A non-aqueous electrolyte battery, which is coated with graphitizing carbon having a size not less than the interplanar spacing (d 002 ) of graphitized carbon serving as a core.
いて、核となる黒鉛化炭素を被覆用黒鉛化炭素で被覆す
るにあたり、この被覆用黒鉛化炭素の量を黒鉛化炭素全
体に対して０．１〜６０重量％の範囲にしたことを特徴
とする非水電解質電池。2. The non-aqueous electrolyte battery according to claim 1, wherein when the graphitized carbon serving as a core is coated with the graphitized carbon for coating, the amount of the graphitized carbon for coating is based on the entire graphitized carbon. A non-aqueous electrolyte battery characterized in that the content is in the range of 0.1 to 60% by weight.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15624596A JP3239068B2 (en) | 1996-05-27 | 1996-05-27 | Non-aqueous electrolyte battery |
| DE69733293T DE69733293T2 (en) | 1996-05-27 | 1997-03-07 | Carbon electrode and battery with non-aqueous electrolyte |
| EP97103887A EP0810680B1 (en) | 1996-05-27 | 1997-03-07 | Non-aqueous electrolyte battery with carbon electrode |
| CA002201556A CA2201556C (en) | 1996-05-27 | 1997-04-02 | Non-aqueous electrolyte battery |
| US08/835,057 US5888671A (en) | 1996-05-27 | 1997-04-03 | Non-aqueous electrolyte battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15624596A JP3239068B2 (en) | 1996-05-27 | 1996-05-27 | Non-aqueous electrolyte battery |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09320597A true JPH09320597A (en) | 1997-12-12 |
| JP3239068B2 JP3239068B2 (en) | 2001-12-17 |
Family
ID=15623560
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15624596A Expired - Lifetime JP3239068B2 (en) | 1996-05-27 | 1996-05-27 | Non-aqueous electrolyte battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3239068B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1040914A (en) * | 1996-05-23 | 1998-02-13 | Sharp Corp | Manufacture of nonaqueous secondary battery and negative pole active substance |
| JP2002279983A (en) * | 2001-03-15 | 2002-09-27 | Sanyo Electric Co Ltd | Lithium secondary battery |
| KR100490464B1 (en) * | 1998-11-27 | 2005-05-17 | 미쓰비시 가가꾸 가부시키가이샤 | Carbonaceous material for electrode and non-aqueous solvent secondary battery using this material |
-
1996
- 1996-05-27 JP JP15624596A patent/JP3239068B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH1040914A (en) * | 1996-05-23 | 1998-02-13 | Sharp Corp | Manufacture of nonaqueous secondary battery and negative pole active substance |
| KR100490464B1 (en) * | 1998-11-27 | 2005-05-17 | 미쓰비시 가가꾸 가부시키가이샤 | Carbonaceous material for electrode and non-aqueous solvent secondary battery using this material |
| JP2002279983A (en) * | 2001-03-15 | 2002-09-27 | Sanyo Electric Co Ltd | Lithium secondary battery |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3239068B2 (en) | 2001-12-17 |
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