JPH08315856A - Lithium secondary battery and manufacture of positive electrode for lithium secondary battery - Google Patents
Lithium secondary battery and manufacture of positive electrode for lithium secondary batteryInfo
- Publication number
- JPH08315856A JPH08315856A JP7114560A JP11456095A JPH08315856A JP H08315856 A JPH08315856 A JP H08315856A JP 7114560 A JP7114560 A JP 7114560A JP 11456095 A JP11456095 A JP 11456095A JP H08315856 A JPH08315856 A JP H08315856A
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- Prior art keywords
- lithium
- positive electrode
- secondary battery
- lithium secondary
- ray
- Prior art date
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Classifications
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- 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
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- Secondary Cells (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明はリチウム二次電池および
リチウム二次電池用正極の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium secondary battery and a method for producing a positive electrode for a lithium secondary battery.
【０００２】[0002]
【従来の技術】近年、電子機器の発達に伴って、その主
電源やメモリーバックアップ用電源として、高性能なリ
チウム二次電池が要望されている。たとえば、コードレ
スホン，コードレス電動工具などのコードレス機器、ビ
デオカメラ，ヘッドホンステレオなどの音響映像機器、
ワードプロセッサー，電子手帳，電子辞書などの文具事
務機器、メモリー内蔵の家電機器、電気自動車、太陽電
池と組み合わせた時計，計算機など、携帯用機器の主電
源やメモリーバックアップ用電源として、長時間かつ経
済的に使用できるリチウム二次電池が要望されている。2. Description of the Related Art In recent years, with the development of electronic equipment, a high-performance lithium secondary battery has been demanded as a main power source and a memory backup power source. For example, cordless devices such as cordless phones and cordless power tools, audiovisual devices such as video cameras and headphone stereos,
Stationary office equipment such as word processors, electronic notebooks, electronic dictionaries, home appliances with built-in memory, electric vehicles, watches combined with solar cells, calculators, etc. There is a demand for a lithium secondary battery that can be used for.
【０００３】ところで、リチウム二次電池においては、
正極活物質として二硫化チタン，五酸化バナジウム，マ
ンガン酸化物などが用いられておりる、資源的に豊富で
安価なマンガン酸化物が注目されている。しかし、マン
ガン酸化物の場合、マンガンと酸素のみで構成（形成）
された二酸化マンガンなどは、可逆性が乏しく充放電特
性が劣るため、たとえばLiMn2 O4 のように、マンガン
酸化物にリチウム塩を導入したリチウムマンガン複合酸
化物の状態で使用することが提案されている（たとえば
米国特許第4,507,371 号明細書）。また、この種のリチ
ウムマンガン複合酸化物としては、前記LiMn2 O4 以外
に、Li2 Mn4 O9 ，Li4 Mn5 O12などのスピネル構造の
化合物［たとえば、Mat.Res.Bull.,25,p 657（199
0）］，さらにはLi2 Mn O3 を含有する二酸化マンガン
（特開昭 63-114064号公報）などが知られている。By the way, in the lithium secondary battery,
Titanium disulfide, vanadium pentoxide, manganese oxide, and the like are used as the positive electrode active material, and resource-rich and inexpensive manganese oxide is drawing attention. However, in the case of manganese oxide, it is composed (formed) of only manganese and oxygen.
Since such manganese dioxide has poor reversibility and poor charge-discharge characteristics, it has been proposed to use it in the state of a lithium manganese composite oxide in which a lithium salt is introduced into manganese oxide, such as LiMn 2 O 4. (For example, US Pat. No. 4,507,371). Further, as the lithium-manganese composite oxide of this type, in addition to the LiMn 2 O 4 , compounds having a spinel structure such as Li 2 Mn 4 O 9 and Li 4 Mn 5 O 12 [for example, Mat.Res.Bull., 25, p 657 (199
[0]], and manganese dioxide containing Li 2 Mn O 3 (JP-A-63-114064) is known.
【０００４】さらに、最近では、 Cukα線によるＸ線回
折パターンにおいて、 2θが19°，21°，33°，37°，
42°，53°および66°付近にピークを有し、かつ21°付
近のピークと19°付近のピークとの強度比 1： 0.7〜
1： 1.2の値を有するリチウムマンガン複合酸化物が、
正極活物質として提案されている（特開平5-174823号公
報）。Furthermore, recently, in the X-ray diffraction pattern by Cuk α-ray, 2θ is 19 °, 21 °, 33 °, 37 °,
It has peaks near 42 °, 53 ° and 66 °, and intensity ratio between peaks near 21 ° and peaks near 19 ° 1: 0.7〜
1: a lithium manganese composite oxide having a value of 1.2,
It has been proposed as a positive electrode active material (Japanese Patent Laid-Open No. 5-174823).
【０００５】[0005]
【発明が解決しようとする課題】しかし、前記リチウム
マンガン複合酸化物は、スピネル系の場合、スピネル構
造において占め得るリチウム（Li）の位置が限定され、
充放電に利用できる有効な電位範囲が小さいという欠点
がある。また、Li2 Mn O3 を含有する二酸化マンガンの
場合は、Li2 Mn O3 が充放電に関与しないため、電池容
量が低下するという問題がある。However, in the case of the spinel-based lithium manganese composite oxide, the position of lithium (Li) that can be occupied in the spinel structure is limited,
There is a drawback that the effective potential range that can be used for charging and discharging is small. In the case of manganese dioxide containing Li 2 Mn O 3, since Li 2 Mn O 3 is not involved in charging and discharging, there is a problem that the battery capacity decreases.
【０００６】本発明は、従来のリチウムマンガン複合酸
化物では、高容量のリチウム二次電池を達成し得ないと
いう問題を解決し、高容量のリチウム二次電池および高
容量リチウム二次電池の構成に適する正極材料の製造方
法を提供することを目的とする。The present invention solves the problem that a conventional lithium-manganese composite oxide cannot achieve a high-capacity lithium secondary battery, and provides a high-capacity lithium secondary battery and a high-capacity lithium secondary battery. It is an object of the present invention to provide a method for producing a positive electrode material suitable for.
【０００７】[0007]
【課題を解決するための手段】本発明に係るリチウム二
次電池は、リチウムイオンを吸蔵・放出する炭素質製の
負極と、リチウムイオン伝導性電解液と、リチウム含有
酸化物からなる正極とを備えたリチウム二次電池におい
て、前記正極はLi2 Mn O3 相およびLiMn2 O 4 相を有
し、かつCu-Kα線によるＸ線回折線の最強線がＩLi2 Mn
O3 ＞ＩLiMn2 O 4 であるリチウム含有酸化物で形成さ
れていることを特徴とする。A lithium secondary battery according to the present invention comprises a carbonaceous negative electrode which absorbs and releases lithium ions, a lithium ion conductive electrolyte, and a positive electrode which comprises a lithium-containing oxide. In the provided lithium secondary battery, the positive electrode has a Li 2 Mn O 3 phase and a LiMn 2 O 4 phase, and the strongest line of the X-ray diffraction line by the Cu-Kα line is ILi 2 Mn.
It is characterized by being formed of a lithium-containing oxide in which O 3 > ILiMn 2 O 4 .
【０００８】本発明に係るリチウム二次電池用正極材料
の製造方法は、電解マンガンおよび硝酸リチウムを、 L
i/Mnのモル比 1/3〜 1/7で混合し、この混合物を 320〜
380℃の温度に加熱することを特徴とする。The method for producing a positive electrode material for a lithium secondary battery according to the present invention comprises:
Mix i / Mn at a molar ratio of 1/3 to 1/7 and mix this mixture from 320 to
It is characterized by heating to a temperature of 380 ° C.
【０００９】本発明は鋭意検討を重ねた結果、 Li/Mnの
モル比を 1/3〜 1/7に選択した電解マンガンおよび硝酸
リチウムの混合粉末を 320℃〜 380℃に加熱（焼成）し
て、合成したリチウム含有酸化物を正極活物質として利
用した場合、リチウム二次電池の高容量化がが容易に達
成されることを見出し、本発明を完成するに至った。す
なわち、前記合成されたリチウム含有酸化物中には、Li
2 Mn O3 相およびLiMn2 O 4 相が含有されており、Cu-K
α線によるＸ線回折線の最強線がＩLi2 Mn O3＞ＩLiMn
2 O 4 の条件を満たしているものを正極活物質とした場
合、高容量のリチウム二次電池として機能することを確
認した。ここで、加熱（焼成）温度が、320℃以下では
未反応の硝酸リチウムが残存しサイクル寿命が低下す
る。また、加熱（焼成）温度が、 380℃以上では前記Cu
-Kα線によるＸ線回折線の最強線がＩLi2 Mn O3 ＜ＩLi
Mn2 O 4 となって、理由は明確でないが電池容量の向上
を図り得ない。そして、ここでの加熱（焼成）時間は、
一般的に 2〜10時間程度である。As a result of extensive studies, the present invention heats (sinters) a mixed powder of electrolytic manganese and lithium nitrate in which the molar ratio of Li / Mn is selected from 1/3 to 1/7 to 320 ° C to 380 ° C. Then, it was found that when the synthesized lithium-containing oxide is used as a positive electrode active material, a high capacity of a lithium secondary battery can be easily achieved, and the present invention has been completed. That is, in the synthesized lithium-containing oxide, Li
Contains 2 Mn O 3 phase and LiMn 2 O 4 phase, Cu-K
The strongest X-ray diffraction line due to α rays is ILi 2 Mn O 3 > ILiMn
It was confirmed that when a positive electrode active material satisfying the conditions of 2 O 4 is used, it functions as a high capacity lithium secondary battery. Here, when the heating (baking) temperature is 320 ° C. or lower, unreacted lithium nitrate remains and the cycle life is reduced. If the heating (firing) temperature is 380 ° C or higher, the Cu content
-The strongest X-ray diffraction line due to Kα rays is ILi 2 Mn O 3 <ILi
It becomes Mn 2 O 4 , but the reason for this is not clear, but the battery capacity cannot be improved. And the heating (firing) time here is
Generally, it is about 2 to 10 hours.
【００１０】なお、前記リチウム含有酸化物の合成に使
用する電解マンガンの平均粒径は、特に制限はないが、
平均粒径 5μm 未満では反応が速過ぎてコントロールが
難しいこと、逆に平均粒径が50μm よりも大きいと反応
速度が遅過ぎるので、平均粒径は約 5〜50μm の範囲に
あることが好ましい。また、電解マンガンの比表面積が
10〜50 m2 /gの範囲にあることが望ましい。その理由
は、比表面積が小さいと反応が進行しにくく、逆に比表
面積が大きすぎると嵩密度が小さくなりすぎ活物質の充
填量が減少して放電容量が低下するからである。The average particle size of electrolytic manganese used in the synthesis of the lithium-containing oxide is not particularly limited,
If the average particle size is less than 5 μm, the reaction is too fast to control, and if the average particle size is more than 50 μm, the reaction rate is too slow. Therefore, the average particle size is preferably in the range of about 5 to 50 μm. Also, the specific surface area of electrolytic manganese
It is desirable to be in the range of 10 to 50 m 2 / g. The reason is that if the specific surface area is small, the reaction is difficult to proceed, and conversely, if the specific surface area is too large, the bulk density becomes too small, and the filling amount of the active material is decreased to lower the discharge capacity.
【００１１】前記リチウム含有酸化物の合成に使用する
硝酸リチウムは、粒径や比表面積に制限はないが、乾式
にて混合する場合は電解マンガンよりも小さい粒径が好
ましい。粒径の調節には混合工程の前にメノウ乳鉢など
で粗粉砕することも適宜行われる。The lithium nitrate used for the synthesis of the lithium-containing oxide is not limited in particle size and specific surface area, but when mixed in a dry system, a particle size smaller than electrolytic manganese is preferable. To adjust the particle size, coarse pulverization may be appropriately performed in an agate mortar or the like before the mixing step.
【００１２】原料配合比は Li/Mnのモル比に換算して 1
/3〜 1/7となる範囲に選ばれる。Li量がMn量の 1/3を超
えると放電容量が低下し、逆にLi量がMn量の 1/7よりも
少なくなると未反応のγ−β相の二酸化マンガンが多く
なり容量が低下する。The raw material compounding ratio is converted to a Li / Mn molar ratio of 1
It is selected in the range of / 3 to 1/7. When the amount of Li exceeds 1/3 of the amount of Mn, the discharge capacity decreases, and conversely, when the amount of Li becomes less than 1/7 of the amount of Mn, the unreacted γ-β phase manganese dioxide increases and the capacity decreases. .
【００１３】[0013]
【作用】本発明に係るリチウム二次電池は、リチウム含
有酸化物中のLi2 Mn O3 相とLiMn2 O4 相のCu-kα線に
よるＸ線回折線の最強線がＩLi2 Mn O3 ＞ＩLiMn2 O4
で表される関係を有するものを特に正極活物質として用
いている。そして、このような正極活物質の使用によっ
て、高容量でかつ充放電サイクル特性にすぐれた信頼性
の高いリチウム二次電池として機能する。In the lithium secondary battery according to the present invention, the strongest X-ray diffraction line by the Cu-kα line of the Li 2 Mn O 3 phase and the LiMn 2 O 4 phase in the lithium-containing oxide is ILi 2 Mn O 3 > ILiMn 2 O 4
In particular, a material having a relationship represented by is used as the positive electrode active material. By using such a positive electrode active material, it functions as a highly reliable lithium secondary battery having high capacity and excellent charge / discharge cycle characteristics.
【００１４】また、本発明に係る正極活物質の製造方法
によれば、上記のように実用上すぐれた機能を呈するリ
チウム二次電池の提供が容易になる。Further, according to the method for producing a positive electrode active material according to the present invention, it becomes easy to provide a lithium secondary battery having a practically excellent function as described above.
【００１５】[0015]
【実施例】次に、図１〜図４を参照して本発明の実施例
を説明する。Embodiments of the present invention will now be described with reference to FIGS.
【００１６】実施例１ 500mlのポリエチレン樹脂製の瓶に、平均粒径約10μm
，比表面積約 15m2 /gの電解二酸化マンガン 100g
と、予めメノウ乳鉢で粗粉砕した硝酸リチウムを配合モ
ル比で Li/Mn＝ 3/7になるように所定量秤量し、これを
約 1時間磁性のボールミルに収容して混合を行った。次
いで、この混合粉末約30g を30mm× 200mmの磁性ボート
に収容して電気炉に挿入し、大気雰囲気下 270℃で予備
焼成を 1時間行った後、 320℃で 5時間加熱焼成して、
リチウム含有酸化物系の正極活物質（試料Ａ）を得た。Example 1 In a 500 ml polyethylene resin bottle, the average particle size was about 10 μm.
, 100g of electrolytic manganese dioxide with a specific surface area of about 15m 2 / g
Then, a predetermined amount of lithium nitrate roughly crushed in an agate mortar in advance was weighed so that the compounding molar ratio was Li / Mn = 3/7, and this was stored in a magnetic ball mill for about 1 hour for mixing. Next, about 30 g of this mixed powder was placed in a magnetic boat of 30 mm × 200 mm, inserted into an electric furnace, pre-baked at 270 ° C for 1 hour in an air atmosphere, and then heated and baked at 320 ° C for 5 hours,
A lithium-containing oxide-based positive electrode active material (Sample A) was obtained.
【００１７】実施例２ 実施例１の場合と同じ配合モル比の混合粉末約30g を、
を30mm× 200mmの磁性ボートに収容して電気炉に挿入
し、大気雰囲気下 270℃での予備焼成を 1時間行った後
350℃で 5時間加熱焼成して、リチウム含有酸化物系の
正極活物質（試料Ｂ）を得た。Example 2 About 30 g of mixed powder having the same compounding molar ratio as in Example 1 was added.
Was stored in a 30 mm × 200 mm magnetic boat, inserted into an electric furnace, and pre-baked at 270 ° C for 1 hour in the air atmosphere.
It was heated and baked at 350 ° C. for 5 hours to obtain a lithium-containing oxide-based positive electrode active material (Sample B).
【００１８】実施例３ 実施例１の場合において、予備焼成後 380℃で 5時間加
熱焼成を行った外は、実施例１の場合と同じ製造条件
で、リチウム含有酸化物系の正極活物質（試料Ｃ）を得
た。Example 3 Under the same manufacturing conditions as in Example 1, except that the pre-baking was followed by heating and baking at 380 ° C. for 5 hours, the lithium-containing oxide-based positive electrode active material ( Sample C) was obtained.
【００１９】実施例４ 実施例１の場合において、 280℃で 1時間予備焼成を行
った外は、実施例１の場合と同じ製造条件で、リチウム
含有酸化物系の正極活物質（試料Ｄ）を得た。 比較例１ 実施例１の場合において、予備焼成後 300℃で 5時間加
熱焼成を行った外は、実施例１の場合と同じ製造条件
で、リチウム含有酸化物系の正極活物質（試料ａ）を得
た。Example 4 A lithium-containing oxide-based positive electrode active material (Sample D) was produced under the same manufacturing conditions as in Example 1 except that pre-baking was performed at 280 ° C. for 1 hour. Got Comparative Example 1 A lithium-containing oxide-based positive electrode active material (Sample a) was produced under the same manufacturing conditions as in Example 1 except that the pre-baking was followed by heating and baking at 300 ° C. for 5 hours. Got
【００２０】比較例２ 実施例１の場合において、予備焼成後 400℃で 5時間加
熱焼成を行った外は、実施例１の場合と同じ製造条件
で、リチウム含有酸化物系の正極活物質（試料ｂ）を得
た。Comparative Example 2 Under the same manufacturing conditions as in Example 1, except that the pre-baking was followed by heating and baking at 400 ° C. for 5 hours in the case of Example 1, a lithium-containing oxide-based positive electrode active material ( A sample b) was obtained.
【００２１】前記実施例１〜４の試料Ａ，Ｂ，Ｃ，Ｄ、
および比較例１〜２の試料ａ，ｂについて、Cu-Kα線に
よるＸ線回折パターンをそれぞれ測定した。Samples A, B, C, D of Examples 1 to 4,
And the X-ray diffraction pattern by Cu-K (alpha) ray was each measured about the samples a and b of Comparative Examples 1-2.
【００２２】図１は試料Ａ，Ｂ，Ｃ、Ｄおよび試料ａ，
ｂのＸ線パターンを、図２は試料Ａ，ＤのＸ線パターン
をそれぞれ示す。ここで、各Ｘ線パターンは各試料に対
応させてＡ，Ｂ，Ｃ，Ｄ，ａ，ｂの記号を付けて表示し
ている。FIG. 1 shows samples A, B, C, D and sample a,
FIG. 2 shows the X-ray pattern of b and FIG. 2 shows the X-ray pattern of samples A and D, respectively. Here, each X-ray pattern is displayed with the symbols A, B, C, D, a, b corresponding to each sample.
【００２３】図１および図２から明らかなように、試料
Ａ〜Ｄ（実施例１〜４）のＸ線回折パターンは、加熱焼
成温度が高くなるにつれてLiMn2 O4 相の回折パターン
が強くなっている以外は類似している。また、試料Ａ，
Ｂ（実施例１，２）は、予備加熱温度が10℃異なってい
るが、類似の回折パターンを示している。As it is apparent from FIGS. 1 and 2, X-ray diffraction pattern of the sample to D (Examples 1-4), the diffraction pattern of LiMn 2 O 4 phase becomes stronger as firing temperature increases Except that they are similar. In addition, sample A,
B (Examples 1 and 2) show similar diffraction patterns, although the preheating temperature differs by 10 ° C.
【００２４】また、試料ａ（比較例１）の場合は、未反
応のLiNO3 相が残存しており、試料Ａ〜Ｄの回折パター
ンと異なっている。一方、試料ｂ（比較例２）の場合
は、存在するLi2 Mn O3 相とLiMn2 O4 相のそれぞれの
Ｘ線回折パターンの最強ピークがＩLi2 Mn O3 ＜ＩLiMn
2 O4 となっており、前記試料Ａ〜ＤのＸ線回折パター
ンと異なっている。In the case of sample a (Comparative Example 1), the unreacted LiNO3 phase remains, which is different from the diffraction patterns of samples A to D. On the other hand, in the case of sample b (Comparative Example 2), the strongest peaks of the X-ray diffraction patterns of the existing Li 2 Mn O 3 phase and LiMn 2 O 4 phase were ILi 2 Mn O 3 <ILiMn
2 O 4 , which is different from the X-ray diffraction patterns of Samples A to D.
【００２５】次に、前記実施例１〜４および比較例１、
２で合成した正極活物質（試料Ａ，Ｂ，Ｃ，Ｄ，ａ，
ｂ）の電池特性を単極評価した。単極評価はそれぞれの
活物質に対して以下のように行った。すなわち、正極
は、上記のそれぞれの活物質を80質量部に対して導電材
のアセチレンブラック（AB）17質量部、および結着剤の
テフロ（PTFE）粉末 3質量部を秤量した。先ず、活物質
とアセチレンブラックを自動乳鉢を用いて10分間混合
し、その後テフロンを加え十分繊維化するまで約10分間
混合した。その後、この混合物をロールプレス機で厚さ
0.25〜0.27mmのシート状に延ばし、集電体であるステン
レスネットに圧着した。Next, Examples 1 to 4 and Comparative Example 1,
2. Positive electrode active material synthesized in 2 (Samples A, B, C, D, a,
The battery characteristics of b) were unipolarly evaluated. Unipolar evaluation was performed as follows for each active material. That is, for the positive electrode, 17 parts by mass of acetylene black (AB) as a conductive material and 3 parts by mass of teflo (PTFE) powder as a binder were weighed with respect to 80 parts by mass of each of the above active materials. First, the active material and acetylene black were mixed in an automatic mortar for 10 minutes, and then Teflon was added and mixed for about 10 minutes until the fibers were sufficiently formed. Then, this mixture is thickened with a roll press.
It was rolled out into a sheet shape of 0.25 to 0.27 mm and pressure-bonded to a stainless steel net as a current collector.
【００２６】このようにして得られた正極シ−トから、
長さ15mm×幅10mmの片をそれぞれ切り出し、活物質部分
が10mm×10mmになるよう調整して測定用電極とした。一
方、負極および参照電極としては、集電体のニッケルネ
ットに圧着されたLi金属箔を用い、また、電解液として
は、エチレンカーボネート（EC）−ジメチルカーボネー
ト（ DMC）の混合溶液に、 1モルの LiClO4 を溶解した
ものを用いた。From the positive electrode sheet thus obtained,
Pieces each having a length of 15 mm and a width of 10 mm were cut out and adjusted so that the active material portion was 10 mm × 10 mm to obtain a measurement electrode. On the other hand, as the negative electrode and the reference electrode, a Li metal foil pressure-bonded to the nickel net of the current collector was used, and as the electrolytic solution, 1 mol of ethylene carbonate (EC) -dimethyl carbonate (DMC) mixed solution was used. A solution of LiClO4 of was used.
【００２７】図３は単極測定試験の実施態様を模式的に
示したもので、次ぎのような手順で単極評価を行った。
すなわち、ガラス製容器１内に、前記電解液２を収容す
る一方、前記測定用正極３の両側に負極４および参照電
極５を配置する形でそれぞれ浸漬した。なお、これらの
電極は３，４，５はそれぞれ充放電試験器６と電気的に
接続される。FIG. 3 schematically shows an embodiment of the unipolar measurement test. The unipolar evaluation was carried out by the following procedure.
That is, the electrolytic solution 2 was housed in the glass container 1, while the negative electrode 4 and the reference electrode 5 were arranged on both sides of the measurement positive electrode 3 so as to be immersed. In addition, these electrodes 3, 4 and 5 are electrically connected to the charge / discharge tester 6, respectively.
【００２８】前記各正極活物質について、充電電圧（充
電終了時）3.5V，放電電圧（放電終了時）2.0Vカし、20
℃に保った恒温槽中で定電流1mA/cm2 による充放電で行
った。図４は、前記単極充放電特性の測定結果を示すも
ので、比較例２の正極活物質（試料ｂ）は初期容量が約
110mAh/gで、実施例１〜４の正極活物質（試料Ａ〜Ｄ）
に比べて容量が小さく、サイクル特性を測定するに値し
なかった。図４より明らかなように実施例１〜４の正極
活物質は、いずれも70サイクルまで放電容量の低下が少
なく良好であるが、比較例１の正極活物質は放電容量の
低下が大きい。For each of the above positive electrode active materials, charge voltage (at the end of charging) 3.5V, discharge voltage (at the end of discharging) 2.0V, 20
It was charged and discharged at a constant current of 1 mA / cm 2 in a constant temperature bath kept at ℃. FIG. 4 shows the measurement results of the single-pole charge / discharge characteristics. The positive electrode active material (Sample b) of Comparative Example 2 had an initial capacity of about
110 mAh / g, positive electrode active material of Examples 1 to 4 (Samples A to D)
The capacity was smaller than that of, and it was not worth measuring the cycle characteristics. As is clear from FIG. 4, all of the positive electrode active materials of Examples 1 to 4 show good decrease in discharge capacity up to 70 cycles, but the positive electrode active material of Comparative Example 1 shows large decrease in discharge capacity.
【００２９】また、前記正極シ−トからそれぞれ切り出
した直径15.1mmの円盤状片、集電体のニッケルネットに
圧着された直径16mmの円盤状Li金属箔（負極）片、エチ
レンカーボネート−ジメチルカーボネート混合溶液に 1
モルの LiClO4 を溶解した電解液、この電解液を担持す
るとともに、正極片と負極片の間に介挿配置するセパレ
ータとを組み合わせ、常套的な手段でボタン型リチウム
二次電池をそれぞれ構成した。これらのボタン型リチウ
ム二次電池について、充放電特性をそれぞれ測定・評価
したところ、前記単極充放電特性に対応した結果が認め
られた。Further, a disc-shaped piece having a diameter of 15.1 mm cut out from each of the positive electrode sheets, a disc-shaped Li metal foil (negative electrode) piece having a diameter of 16 mm crimped to a nickel net of a current collector, ethylene carbonate-dimethyl carbonate 1 to mixed solution
A button-type lithium secondary battery was constructed by a conventional means by combining an electrolytic solution in which a molar amount of LiClO4 was dissolved and a separator which supported the electrolytic solution and was interposed between the positive electrode piece and the negative electrode piece. The charge / discharge characteristics of these button-type lithium secondary batteries were measured and evaluated, respectively, and the results corresponding to the single-pole charge / discharge characteristics were found.
【００３０】なお、本発明は上記実施例に限定されるも
のでなく、発明の趣旨を逸脱しない範囲でいろいろの変
形を採ることができる。The present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the invention.
【００３１】[0031]
【発明の効果】以上に説明したように、本発明によれ
ば、電解マンガンおよび硝酸リチウムを320℃〜 380℃
の温度に加熱して合成され、かつ含まれている化合物の
うち、Li2 Mn O3 相とLiMn2 O4 相のCu-kα線によるＸ
線回折線の最強線がＩLi2 Mn O3＞ＩLiMn2 O4 で表さ
れる関係を有する正極活物質を用いる。そして、このよ
うな正極活物質の応用・利用によって、高容量でかつ充
放電サイクル特性にすぐれたリチウム二次電池の提供が
可能となった。As described above, according to the present invention, electrolytic manganese and lithium nitrate are added at 320 ° C to 380 ° C.
Of the compounds synthesized and heated by heating to the temperature of Li 2 Mn O 3 phase and LiMn 2 O 4 phase by Cu-kα ray
A positive electrode active material having a relationship in which the strongest line of the line diffraction lines is represented by ILi 2 Mn O 3 > ILiMn 2 O 4 is used. By applying and using such a positive electrode active material, it has become possible to provide a lithium secondary battery having a high capacity and excellent charge / discharge cycle characteristics.
【図１】本発明に係るリチウム二次電池が具備する正極
活物質のＸ線回折線パターン例を本発明外の正極活物質
のＸ線回折線パターンと比較して示す曲線図。FIG. 1 is a curve diagram showing an example of an X-ray diffraction line pattern of a positive electrode active material included in a lithium secondary battery according to the present invention in comparison with an X-ray diffraction line pattern of a positive electrode active material other than the present invention.
【図２】本発明に係るリチウム二次電池が具備する正極
活物質のＸ線回折線パターン例を比較して示す曲線図。FIG. 2 is a curve diagram showing a comparison of X-ray diffraction line pattern examples of the positive electrode active material included in the lithium secondary battery according to the present invention.
【図３】リチウム二次電池が具備する正極活物質につい
て単極充放電特性の評価・測定の実施態様を示す模式
図。FIG. 3 is a schematic diagram showing an embodiment of evaluation / measurement of single-pole charge / discharge characteristics of a positive electrode active material included in a lithium secondary battery.
【図４】本発明に係るリチウム二次電池例および本発明
外のリチウム二次電池について放電比容量変化を比較し
て示す曲線図。FIG. 4 is a curve diagram showing changes in discharge specific capacities of an example of a lithium secondary battery according to the present invention and a lithium secondary battery outside the present invention.
１………ガラス製容器 ２………電解液 ３………正極 ４………負極 ５………参照電極 ６………充放電試験器 1 ... Glass container 2 ... Electrolyte 3 ... Positive electrode 4 ... Negative electrode 5 ... Reference electrode 6 ... Charge / discharge tester
───────────────────────────────────────────────────── フロントページの続き (72)発明者 安斎 和雄 東京都品川区南品川３丁目４番10号 東芝 電池株式会社内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuo Ansai 3-4-10 Minamishinagawa, Shinagawa-ku, Tokyo Inside Toshiba Battery Co., Ltd.
Claims (2)
製の負極と、リチウムイオン伝導性電解液と、リチウム
含有酸化物からなる正極とを備えたリチウム二次電池に
おいて、 前記正極はLi2 Mn O3 相およびLiMn2 O 4 相を有し、か
つCu-Kα線によるＸ線回折線の最強線がＩLi2 Mn O3 ＞
ＩLiMn2 O 4 であるリチウム含有酸化物で形成されてい
ることを特徴とするリチウム二次電池。1. A lithium secondary battery comprising a carbonaceous negative electrode that absorbs and releases lithium ions, a lithium ion conductive electrolyte, and a positive electrode composed of a lithium-containing oxide, wherein the positive electrode is Li 2 Mn. It has an O 3 phase and a LiMn 2 O 4 phase, and the strongest line of the X-ray diffraction line by Cu-Kα ray is ILi 2 Mn O 3 >
A lithium secondary battery, which is formed of a lithium-containing oxide which is ILiMn 2 O 4 .
i/Mnのモル比 1/3〜1/7で混合し、この混合物を 320〜
380℃の温度に加熱することを特徴とするリチウム二次
電池用正極材料の製造方法。2. Electrolytic manganese and lithium nitrate are added to L
Mix i / Mn at a molar ratio of 1/3 to 1/7 and mix this mixture from 320 to
A method for producing a positive electrode material for a lithium secondary battery, which comprises heating to a temperature of 380 ° C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7114560A JPH08315856A (en) | 1995-05-12 | 1995-05-12 | Lithium secondary battery and manufacture of positive electrode for lithium secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7114560A JPH08315856A (en) | 1995-05-12 | 1995-05-12 | Lithium secondary battery and manufacture of positive electrode for lithium secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH08315856A true JPH08315856A (en) | 1996-11-29 |
Family
ID=14640873
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7114560A Withdrawn JPH08315856A (en) | 1995-05-12 | 1995-05-12 | Lithium secondary battery and manufacture of positive electrode for lithium secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH08315856A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2011040383A1 (en) * | 2009-09-30 | 2011-04-07 | 戸田工業株式会社 | Positive electrode active material powder, method for producing same, and nonaqueous electrolyte secondary battery |
| CN108963217A (en) * | 2004-09-03 | 2018-12-07 | 芝加哥大学阿尔贡有限责任公司 | Manganese oxide composite electrodes for lithium batteries |
-
1995
- 1995-05-12 JP JP7114560A patent/JPH08315856A/en not_active Withdrawn
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108963217A (en) * | 2004-09-03 | 2018-12-07 | 芝加哥大学阿尔贡有限责任公司 | Manganese oxide composite electrodes for lithium batteries |
| CN108963217B (en) * | 2004-09-03 | 2022-05-03 | 芝加哥大学阿尔贡有限责任公司 | Manganese oxide composite electrode for lithium battery |
| WO2011040383A1 (en) * | 2009-09-30 | 2011-04-07 | 戸田工業株式会社 | Positive electrode active material powder, method for producing same, and nonaqueous electrolyte secondary battery |
| US9249034B2 (en) | 2009-09-30 | 2016-02-02 | Toda Kogyo Corporation | Positive electrode active substance particles and process for producing the same, and non-aqueous electrolyte secondary battery |
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