JP2000021405A - Lithium secondary battery - Google Patents

Lithium secondary battery

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Publication number
JP2000021405A
JP2000021405A JP10202795A JP20279598A JP2000021405A JP 2000021405 A JP2000021405 A JP 2000021405A JP 10202795 A JP10202795 A JP 10202795A JP 20279598 A JP20279598 A JP 20279598A JP 2000021405 A JP2000021405 A JP 2000021405A
Authority
JP
Japan
Prior art keywords
lithium
peak
secondary battery
positive electrode
lithium 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.)
Pending
Application number
JP10202795A
Other languages
Japanese (ja)
Inventor
Hiroshi Nakajima
中島  宏
Hiroshi Watanabe
浩志 渡辺
Toshiyuki Noma
俊之 能間
Koji Nishio
晃治 西尾
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.)
Sanyo Electric Co Ltd
Original Assignee
Sanyo Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sanyo Electric Co Ltd filed Critical Sanyo Electric Co Ltd
Priority to JP10202795A priority Critical patent/JP2000021405A/en
Publication of JP2000021405A publication Critical patent/JP2000021405A/en
Pending legal-status Critical Current

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Classifications

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

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  • Secondary Cells (AREA)
  • Battery Electrode And Active Subsutance (AREA)

Abstract

PROBLEM TO BE SOLVED: To provide a lithium secondary battery including lithium manganate which has large discharging capacity as the positive electrode active material. SOLUTION: A lithium secondary battery includes the positive electrode active material of lithium manganate expressed with composition formula LixMOy (x means a value which fluctuates in response to the charging and discharging condition, 0<=x<=1.2; 1.9<=y<=2.1) and having each peak P1, P2, P3, P4 in order in four ranges of 18.2 deg.<2θ<18.6 deg., 24.6 deg.<2θ<25.1 deg., 44.6 deg.<2θ<45.0 deg. and 45.0 deg.<2θ<45.4 deg. (where 2θ is diffraction angle) in an X-ray diffraction profile to be obtained by using CuKα beam of the lithium manganate having the composition x=1 as a beam source.

Description

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

【0001】[0001]

【発明が属する技術分野】本発明は、マンガン酸リチウ
ムを正極活物質とするリチウム二次電池に係わり、特
に、放電容量が大きいリチウム二次電池を提供すること
を目的とした、前記マンガン酸リチウムの改良に関す
る。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lithium secondary battery using lithium manganate as a positive electrode active material, and in particular, to provide a lithium secondary battery having a large discharge capacity. Regarding improvement.

【0002】[0002]

【従来の技術及び発明が解決しようとする課題】リチウ
ム二次電池の正極活物質としては、コバルト酸リチウム
(LiCoO2)、ニッケル酸リチウム(LiNi
2 )及びリチウム・ニッケル・コバルト複合酸化物
(LiNiz Co1-z 2 (0<z<1)など)が良く
知られており、これらを使用することにより、高電圧
で、しかも放電容量の大きいリチウム二次電池を得るこ
とが可能である。
2. Description of the Related Art Lithium cobaltate (LiCoO 2 ) and lithium nickelate (LiNiO 2 ) are used as a positive electrode active material of a lithium secondary battery.
O 2 ) and lithium-nickel-cobalt composite oxides (LiNi z Co 1 -z O 2 (0 <z <1) and the like) are well known. It is possible to obtain a lithium secondary battery having a large capacity.

【0003】しかしながら、上記の正極活物質には、コ
バルト原料及びニッケル原料がいずれも高価なために高
価であり、電池製造コストが高くつくという問題があ
る。
[0003] However, the above-mentioned positive electrode active material is expensive because both the cobalt raw material and the nickel raw material are expensive, and there is a problem that the battery manufacturing cost is high.

【0004】比較的安価な原料から得られる正極活物質
としては、LiMn2 4 に代表されるスピネル型マン
ガン酸リチウムが知られているが、理論放電容量が14
8mAh/gと小さいので、実際の放電容量も小さい。
理論放電容量の大きいマンガン酸リチウムとしては、L
iMnO2 (斜方晶系マンガン酸リチウム)が知られて
いるが、これも理由は定かでないが実際の放電容量は小
さい。また、特開平7−230802号では、少なくと
も、15.2°<2θ<15.6°、18.6°<2θ
<18.8°及び24.5°<2θ<25.1°(2
θ:回折角)の3つの範囲にそれぞれピークを有するマ
ンガン酸リチウムが提案されているが、本発明者らが調
べたところによれば、これも実際の放電容量は小さい。
As a positive electrode active material obtained from relatively inexpensive raw materials, spinel-type lithium manganate represented by LiMn 2 O 4 is known, but the theoretical discharge capacity is 14%.
Since it is as small as 8 mAh / g, the actual discharge capacity is also small.
As lithium manganate having a large theoretical discharge capacity, L
Although iMnO 2 (orthorhombic lithium manganate) is known, the reason for this is not clear, but the actual discharge capacity is small. Also, in JP-A-7-230802, at least 15.2 ° <2θ <15.6 ° and 18.6 ° <2θ.
<18.8 ° and 24.5 ° <2θ <25.1 ° (2
Lithium manganate having respective peaks in three ranges of θ (diffraction angle) has been proposed, but according to investigations by the present inventors, the actual discharge capacity is also small.

【0005】本発明は、以上の事情に鑑みなされたもの
であって、放電容量が大きい、マンガン酸リチウムを正
極活物質とするリチウム二次電池を提供することを目的
とする。
The present invention has been made in view of the above circumstances, and has as its object to provide a lithium secondary battery having a large discharge capacity and using lithium manganate as a positive electrode active material.

【0006】[0006]

【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(本発明電池)は、マンガン酸リチウムを正極活
物質とするリチウム二次電池であり、前記マンガン酸リ
チウムが、組成式Lix MnOy (xは充放電状態によ
り変動する値であり、0≦x≦1.2;1.9≦y≦
2.1)で表され、且つx=1の組成のマンガン酸リチ
ウムのCuKα線を線源として得られるX線回折プロフ
ァイルにおいて、少なくとも、18.2°<2θ<1
8.6°、24.6°<2θ<25.1°、44.6°
<2θ<45.0°及び45.0°<2θ<45.4°
(2θ:回折角)の4つの範囲に、順に、それぞれピー
クP1 ,P2 ,P3 及びP4 を一つずつ有することを特
徴とする。
A lithium secondary battery (battery of the present invention) according to the present invention is a lithium secondary battery using lithium manganate as a positive electrode active material, wherein the lithium manganate has a composition formula Li x MnO y (x is a value that varies depending on the charge / discharge state, and 0 ≦ x ≦ 1.2; 1.9 ≦ y ≦
In the X-ray diffraction profile obtained by using the CuKα ray of lithium manganate having the composition of 2.1) and having a composition of x = 1 as a radiation source, at least 18.2 ° <2θ <1
8.6 °, 24.6 ° <2θ <25.1 °, 44.6 °
<2θ <45.0 ° and 45.0 ° <2θ <45.4 °
It is characterized in that each of the four ranges (2θ: diffraction angle) has one peak P 1 , P 2 , P 3, and P 4 respectively in order.

【0007】マンガン酸リチウムとしては、ピークP1
に対するピークP2 のピーク強度比が、0.1〜1.5
のもの、及び、ピークP4 に対するピークP3 のピーク
強度比が、0.1〜1.0のものが、放電容量が大きい
リチウム二次電池を得る上で、好ましい。また、マンガ
ン酸リチウムとしては、メジアン径5〜20μmの粉末
が、放電容量が大きいリチウム二次電池を得る上で、好
ましい。
For lithium manganate, the peak P 1
Peak intensity ratio of the peak P 2 for the 0.1 to 1.5
Ones, and the peak intensity ratio of the peak P 3 with respect to the peak P 4 is, those 0.1 to 1.0, in terms of the discharge capacity to obtain a large lithium secondary battery, preferable. As lithium manganate, powder having a median diameter of 5 to 20 μm is preferable for obtaining a lithium secondary battery having a large discharge capacity.

【0008】本発明は、正極活物質たるマンガン酸リチ
ウムの改良に関する。それゆえ、他の電池材料について
は、リチウム二次電池用として従来公知の種々の材料を
使用することができる。負極材料としては、リチウムイ
オンを電気化学的に吸蔵及び放出することが可能な物質
又は金属リチウムが例示される。リチウムイオンを電気
化学的に吸蔵及び放出することが可能な物質としては、
黒鉛(天然黒鉛及び人造黒鉛)、コークス、有機物焼成
体等の炭素材料や、リチウム−アルミニウム合金、リチ
ウム−マグネシウム合金、リチウム−インジウム合金、
リチウム−錫合金、リチウム−タリウム合金、リチウム
−鉛合金、リチウム−ビスマス合金等のリチウム合金、
及び錫、チタン、鉄、モリブデン、ニオブ、バナジウム
及び亜鉛を一種又は二種以上含む、金属酸化物(SnO
2 、SnO、TiO2 、Nb2 3 など)及び金属硫化
物が例示される。また、電解液の溶質としては、LiC
lO4 、LiCF3 SO3 、LiPF6 、LiN(CF
3 SO2 2 、LiN(C2 5 SO2 2 、LiBF
4 、LiSbF6 、LiAsF6 等のリチウム塩が例示
され、溶媒としては、エチレンカーボネート、プロピレ
ンカーボネート、ビニレンカーボネート、ブチレンカー
ボネート等の環状炭酸エステル、及び、環状炭酸エステ
ルと、ジメチルカーボネート、ジエチルカーボネート、
メチルエチルカーボネート、1,2−ジメトキシエタ
ン、1,2−ジエトキシエタン、1,2−エトキシメト
キシエタン等の低沸点溶媒との混合溶媒が例示される。
[0008] The present invention relates to an improvement of lithium manganate as a positive electrode active material. Therefore, as other battery materials, conventionally known various materials for lithium secondary batteries can be used. Examples of the negative electrode material include a substance capable of electrochemically storing and releasing lithium ions and metallic lithium. Substances that can occlude and release lithium ions electrochemically include:
Carbon materials such as graphite (natural graphite and artificial graphite), coke, fired organic materials, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy,
Lithium alloys such as lithium-tin alloy, lithium-thallium alloy, lithium-lead alloy, lithium-bismuth alloy,
And a metal oxide (SnO) containing one or more of tin, titanium, iron, molybdenum, niobium, vanadium and zinc.
2, SnO, etc. TiO 2, Nb 2 O 3) and metal sulfides are exemplified. The solute of the electrolyte is LiC
10 4 , LiCF 3 SO 3 , LiPF 6 , LiN (CF
3 SO 2 ) 2 , LiN (C 2 F 5 SO 2 ) 2 , LiBF
4, LiSbF 6, LiAsF 6 and lithium salt are exemplified in, as the solvent, ethylene carbonate, propylene carbonate, vinylene carbonate, cyclic carbonate such as butylene carbonate and a cyclic carbonate, dimethyl carbonate, diethyl carbonate,
Examples thereof include a mixed solvent with a low boiling point solvent such as methyl ethyl carbonate, 1,2-dimethoxyethane, 1,2-diethoxyethane, and 1,2-ethoxymethoxyethane.

【0009】CuKα線を線源とするX線回折法で得ら
れるX線回折プロファイルにおいて、特定の4つの2θ
領域にそれぞれピークを有する、比容量が大きい特定の
マンガン酸リチウムを正極活物質として使用しているの
で、本発明電池は放電容量が大きい。
In an X-ray diffraction profile obtained by an X-ray diffraction method using CuKα radiation as a source, four specific 2θ
Since the specific lithium manganate having a large specific capacity and having a peak in each region is used as the positive electrode active material, the battery of the present invention has a large discharge capacity.

【0010】[0010]

【実施例】本発明を実施例に基づいてさらに詳細に説明
するが、本発明は下記実施例に何ら限定されるものでは
なく、その要旨を変更しない範囲で適宜変更して実施す
ることが可能なものである。
EXAMPLES The present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples and can be carried out by appropriately changing the scope of the invention without changing its gist. It is something.

【0011】(実施例1〜7) 〔正極の作製〕水酸化リチウム(LiOH)と三酸化二
マンガン(Mn2 3 )とをモル比2:1で混合し、ア
ルゴン雰囲気下にて、550°C、600°C、650
°C、700°C、750°C、800°C又は850
°Cで12時間加熱処理した後、ジェットミルで粉砕し
て、メジアン径10μmの組成式LiMnO2 で表され
る7種の正極活物質としてのマンガン酸リチウム粉末
(a1)〜(a7)を作製した。
(Examples 1 to 7) [Preparation of Positive Electrode] Lithium hydroxide (LiOH) and dimanganese trioxide (Mn 2 O 3 ) were mixed at a molar ratio of 2: 1 and 550 in an argon atmosphere. ° C, 600 ° C, 650
° C, 700 ° C, 750 ° C, 800 ° C or 850
After heat treatment at 12 ° C. for 12 hours, the mixture is pulverized by a jet mill to produce seven kinds of lithium manganate powders (a1) to (a7) having a median diameter of 10 μm as seven kinds of positive electrode active materials represented by the composition formula LiMnO 2. did.

【0012】上記の各マンガン酸リチウム粉末と、導電
剤としてのアセチレンブラックと、結着剤としてのポリ
フッ化ビニリデンとを重量比90:6:4で混練して正
極合剤を作製し、この正極合剤を2トン/cm2 の圧力
で直径20mmの円盤状に加圧成型した後、真空中にて
250°Cで2時間加熱処理して、正極を作製した。
The above lithium manganate powder, acetylene black as a conductive agent, and polyvinylidene fluoride as a binder are kneaded at a weight ratio of 90: 6: 4 to prepare a positive electrode mixture. The mixture was press-molded into a disc having a diameter of 20 mm at a pressure of 2 ton / cm 2 , and then heat-treated at 250 ° C. for 2 hours in a vacuum to produce a positive electrode.

【0013】〔負極の作製〕リチウム−アルミニウム合
金の圧延板から直径20mmの円盤を打ち抜いて、負極
を作製した。
[Preparation of Negative Electrode] A disk having a diameter of 20 mm was punched from a rolled sheet of a lithium-aluminum alloy to prepare a negative electrode.

【0014】〔電解液の調製〕エチレンカーボネートと
ジメチルカーボネートの体積比1:1の混合溶媒に、L
iPF6 を1モル/リットル溶かして電解液を調製し
た。
[Preparation of Electrolyte Solution] A mixed solvent of ethylene carbonate and dimethyl carbonate having a volume ratio of 1: 1 was mixed with L
iPF 6 was prepared an electrolytic solution dissolving 1 mol / liter.

【0015】〔リチウム二次電池の作製〕上記の正極、
負極及び電解液を使用して、常法により扁平形のリチウ
ム二次電池(本発明電池)(A1)〜(A7)を作製し
た。セパレータには、イオン透過性のポリプロピレンフ
ィルムを使用した。また、正極と負極の容量比を1:
1.1とし、電池容量が正極容量により規制されるよう
にした。以下の電池も正極と負極の容量比を全て1:
1.1とした。図1は、ここで作製したリチウム二次電
池(A)の断面図であり、同図に示す電池(A)は、正
極(1)、負極(2)、これらを離間するセパレータ
(3)、正極缶(4)、負極缶(5)、正極集電体
(6)、負極集電体(7)、絶縁パッキング(8)など
からなる。正極(1)及び負極(2)は、セパレータ
(3)を介して対向して正極缶(4)及び負極缶(5)
が形成する電池缶内に収容されており、正極(1)は正
極集電体(6)を介して正極缶(4)に、負極(2)は
負極集電体(7)を介して負極缶(5)に、それぞれ接
続され、電池内部に生じた化学エネルギーを電気エネル
ギーとして外部へ取り出し得るようになっている。
[Preparation of lithium secondary battery]
Using the negative electrode and the electrolytic solution, flat lithium secondary batteries (batteries of the present invention) (A1) to (A7) were produced by a conventional method. An ion-permeable polypropylene film was used for the separator. Further, the capacity ratio between the positive electrode and the negative electrode is 1:
1.1, the battery capacity was regulated by the positive electrode capacity. Also in the following batteries, the capacity ratio of the positive electrode to the negative electrode was all 1:
1.1. FIG. 1 is a cross-sectional view of the lithium secondary battery (A) manufactured here. The battery (A) shown in FIG. 1 has a positive electrode (1), a negative electrode (2), a separator (3) separating these, It comprises a positive electrode can (4), a negative electrode can (5), a positive electrode current collector (6), a negative electrode current collector (7), an insulating packing (8) and the like. The positive electrode (1) and the negative electrode (2) face each other with the separator (3) interposed therebetween, and the positive electrode can (4) and the negative electrode can (5)
The positive electrode (1) is accommodated in a positive electrode can (4) via a positive electrode current collector (6), and the negative electrode (2) is accommodated in a negative electrode current collector (7) via a negative electrode current collector (7). Chemical energy generated inside the battery is connected to the can (5), and can be taken out to the outside as electric energy.

【0016】(実施例8〜14)水酸化リチウムと60
0°Cで20時間加熱処理した二酸化マンガン(MnO
2 )とをモル比1:1で混合し、アルゴン雰囲気下に
て、550°C、600°C、650°C、700°
C、750°C、800°C又は850°Cで12時間
加熱処理した後、ジェットミルで粉砕して、メジアン径
10μmの組成式LiMnO2 で表される7種の正極活
物質としてのマンガン酸リチウム粉末(a8)〜(a1
4)を作製した。正極活物質として上記の各マンガン酸
リチウム粉末を使用したこと以外は実施例1〜7と同様
にして、本発明電池(A8)〜(A14)を作製した。
Examples 8 to 14 Lithium hydroxide and 60
Manganese dioxide (MnO) heated at 0 ° C for 20 hours
2 ) and 550 ° C, 600 ° C, 650 ° C, 700 ° under an argon atmosphere.
C, 750 ° C., 800 ° C. or 850 ° C., heat-treated for 12 hours, then pulverized by a jet mill to obtain a manganese acid having seven median diameters of 10 μm and represented by the composition formula LiMnO 2 as a positive electrode active material. Lithium powder (a8) to (a1
4) was produced. Batteries (A8) to (A14) of the present invention were produced in the same manner as in Examples 1 to 7, except that each of the above lithium manganate powders was used as the positive electrode active material.

【0017】(比較例1〜5)Li2 MnO3 と一酸化
マンガン(MnO)とをモル比1:1で混合し、アルゴ
ン雰囲気下にて、800°C、850°C、900°
C、950°C又は1000°Cで12時間加熱処理し
た後、ジェットミルで粉砕して、メジアン径10μmの
組成式LiMnO2 で表される5種の正極活物質として
のマンガン酸リチウム粉末(b1)〜(b5)を作製し
た。正極活物質として上記の各マンガン酸リチウム粉末
を使用したこと以外は実施例1〜7と同様にして、比較
電池(B1)〜(B5)を作製した。
(Comparative Examples 1 to 5) Li 2 MnO 3 and manganese monoxide (MnO) were mixed at a molar ratio of 1: 1 and were mixed at 800 ° C., 850 ° C., and 900 ° C. in an argon atmosphere.
C, heat-treated at 950 ° C. or 1000 ° C. for 12 hours, and then pulverized by a jet mill to obtain five kinds of lithium manganate powders (b1) having a median diameter of 10 μm as five kinds of cathode active materials represented by a composition formula LiMnO 2 ) To (b5). Comparative batteries (B1) to (B5) were produced in the same manner as in Examples 1 to 7, except that each of the above lithium manganate powders was used as the positive electrode active material.

【0018】(比較例6〜10)炭酸リチウム(Li2
CO3 )と炭酸マンガン(MnCO3 )とをモル比1:
2で混合し、アルゴン雰囲気下にて、800°C、85
0°C、900°C、950°C又は1000°Cで1
2時間加熱処理した後、ジェットミルで粉砕して、メジ
アン径10μmの組成式LiMnO2 で表される5種の
正極活物質としてのマンガン酸リチウム粉末(b6)〜
(b10)を作製した。正極活物質として上記の各マン
ガン酸リチウム粉末を使用したこと以外は実施例1〜7
と同様にして、比較電池(B6)〜(B10)を作製し
た。
Comparative Examples 6 to 10 Lithium carbonate (Li 2
CO 3 ) and manganese carbonate (MnCO 3 ) in a molar ratio of 1:
2 at 800 ° C., 85 ° C. under an argon atmosphere.
1 at 0 ° C, 900 ° C, 950 ° C or 1000 ° C
After heat treatment for 2 hours, the mixture is pulverized by a jet mill, and lithium manganate powder (b6) as five kinds of positive electrode active materials represented by composition formula LiMnO 2 having a median diameter of 10 μm to
(B10) was produced. Examples 1 to 7 except that each of the above lithium manganate powders was used as a positive electrode active material.
In the same manner as in the above, comparative batteries (B6) to (B10) were produced.

【0019】(比較例11〜15)水酸化リチウムと二
酸化マンガンとをモル比1:1で混合し、チッソガス雰
囲気下にて、600°C、650°C、700°C、7
50°C又は800°Cで3時間加熱処理した後、ジェ
ットミルで粉砕して、メジアン径10μmの組成式Li
MnO2 で表される5種の正極活物質としてのマンガン
酸リチウム粉末(b11)〜(b15)を作製した。正
極活物質として上記の各マンガン酸リチウム粉末を使用
したこと以外は実施例1〜7と同様にして、比較電池
(B11)〜(B15)を作製した。比較電池(B1
1)〜(B15)は、特開平7−23802号に開示の
方法に準拠して作製された電池である。
(Comparative Examples 11 to 15) Lithium hydroxide and manganese dioxide were mixed at a molar ratio of 1: 1 and mixed at 600 ° C., 650 ° C., 700 ° C., and 7 ° C. under a nitrogen gas atmosphere.
After heat treatment at 50 ° C. or 800 ° C. for 3 hours, the mixture is pulverized by a jet mill to obtain a composition formula Li having a median diameter of 10 μm.
Lithium manganate powders (b11) to (b15) as five kinds of positive electrode active materials represented by MnO 2 were produced. Comparative batteries (B11) to (B15) were produced in the same manner as in Examples 1 to 7, except that each of the above lithium manganate powders was used as the positive electrode active material. Comparative battery (B1
1) to (B15) are batteries manufactured according to the method disclosed in JP-A-7-23802.

【0020】実施例1〜14及び比較例1〜15で正極
活物質として使用した各マンガン酸リチウム粉末につい
てCuKα線を線源とするX線回折のプロファイルを測
定した。図2は、実施例3で作製したマンガン酸リチウ
ム粉末(a3)のX線回折図であり、同図に示すよう
に、18.2°<2θ<18.6°、24.6°<2θ
<25.1°、44.6°<2θ<45.0°及び4
5.0°<2θ<45.4°(2θ:回折角)の4つの
範囲に、それぞれ1つずつピークを有していた。実施例
1,2,4〜14で作製したマンガン酸リチウム粉末
(a1),(a2),(a4)〜(a14)のX線回折
図も、上記の4つの範囲に、それぞれ1つずつピークを
有していた。図3は、比較例3で作製したマンガン酸リ
チウム粉末(b3)のX線回折図であり、同図に示すよ
うに、24.6°<2θ<25.1°及び45.0°<
2θ<45.4°の各範囲にそれぞれ1つずつピークを
有していたが、18.2°<2θ<18.6°及び4
4.6°<2θ<45.0°の各範囲には、ピークを有
していなかった。比較例1,2,4〜10で作製したマ
ンガン酸リチウム粉末(b1),(b2),(b4)〜
(b10)のX線回折図も、24.6°<2θ<25.
1°及び45.0°<2θ<45.4°の各範囲にそれ
ぞれ1つずつピークを有していたが、18.2°<2θ
<18.6°及び44.6°<2θ<45.0°の各範
囲には、ピークを有していなかった。図4は、比較例1
3で作製したマンガン酸リチウム粉末(b13)のX線
回折図であり、同図に示すように、24.6°<2θ<
25.1°及び45.0°<2θ<45.4°の各範囲
にそれぞれ1つずつピークを有していたが、18.2°
<2θ<18.6°及び44.6°<2θ<45.0°
の各範囲には、ピークを有していなかった。各X線回折
図について、18.2°<2θ<18.6°、24.6
°<2θ<25.1°、44.6°<2θ<45.0°
及び45.0°<2θ<45.4°の4つの範囲に存在
する各ピークのピーク位置2θ、18.2°<2θ<1
8.6°の範囲に存在するピークP1 に対する24.6
°<2θ<25.1°の範囲に存在するピークP2 のピ
ーク強度比(P2 /P1 )、及び、45.0°<2θ<
45.4°の範囲に存在するピークP4 に対する44.
6°<2θ<45.0°の範囲に存在するピークP3
ピーク強度比(P3 /P4 )を求めた。実施例1〜14
で使用した各マンガン酸リチウム粉末の結果を表1に、
比較例1〜15で使用した各マンガン酸リチウム粉末の
結果を表2に、それぞれ示す。なお、表1及び表2中の
「範囲1」、「範囲2」、「範囲3」及び「範囲4」
は、それぞれ18.2°<2θ<18.6°、24.6
°<2θ<25.1°、44.6°<2θ<45.0°
及び45.0°<2θ<45.4°の各範囲を表す。
For each lithium manganate powder used as a positive electrode active material in Examples 1 to 14 and Comparative Examples 1 to 15, X-ray diffraction profiles using CuKα radiation as a radiation source were measured. FIG. 2 is an X-ray diffraction diagram of the lithium manganate powder (a3) produced in Example 3, and as shown in the figure, 18.2 ° <2θ <18.6 °, 24.6 ° <2θ.
<25.1 °, 44.6 ° <2θ <45.0 ° and 4
There was one peak in each of four ranges of 5.0 ° <2θ <45.4 ° (2θ: diffraction angle). The X-ray diffraction patterns of the lithium manganate powders (a1), (a2), (a4) to (a14) produced in Examples 1, 2, 4 to 14 also show one peak in each of the above four ranges. Had. FIG. 3 is an X-ray diffraction diagram of the lithium manganate powder (b3) produced in Comparative Example 3, and as shown in the figure, 24.6 ° <2θ <25.1 ° and 45.0 ° <
Although each had one peak in each range of 2θ <45.4 °, 18.2 ° <2θ <18.6 ° and 4
There was no peak in each range of 4.6 ° <2θ <45.0 °. Lithium manganate powders (b1), (b2) and (b4) produced in Comparative Examples 1, 2, 4 to 10
The X-ray diffraction pattern of (b10) is also 24.6 ° <2θ <25.
Although each had one peak in each range of 1 ° and 45.0 ° <2θ <45.4 °, 18.2 ° <2θ.
There was no peak in each range of <18.6 ° and 44.6 ° <2θ <45.0 °. FIG. 4 shows Comparative Example 1.
3 is an X-ray diffraction diagram of the lithium manganate powder (b13) produced in Example 3, and as shown in the drawing, 24.6 ° <2θ <
Although there was one peak in each range of 25.1 ° and 45.0 ° <2θ <45.4 °, 18.2 °
<2θ <18.6 ° and 44.6 ° <2θ <45.0 °
Did not have a peak in each range. For each X-ray diffraction diagram, 18.2 ° <2θ <18.6 °, 24.6
° <2θ <25.1 °, 44.6 ° <2θ <45.0 °
And peak positions 2θ, 18.2 ° <2θ <1 of each peak existing in four ranges of 45.0 ° <2θ <45.4 °.
24.6 with respect to the peak P 1 present in the range of 8.6 °
The peak intensity ratio (P 2 / P 1 ) of the peak P 2 existing in the range of ° <2θ <25.1 °, and 45.0 ° <2θ <
44 with respect to the peak P 4 that is present in the range of 45.4 °.
The peak intensity ratio (P 3 / P 4 ) of the peak P 3 existing in the range of 6 ° <2θ <45.0 ° was determined. Examples 1 to 14
Table 1 shows the results of each lithium manganate powder used in
Table 2 shows the results of the respective lithium manganate powders used in Comparative Examples 1 to 15. Note that “Range 1”, “Range 2”, “Range 3” and “Range 4” in Tables 1 and 2
Are 18.2 ° <2θ <18.6 ° and 24.6, respectively.
° <2θ <25.1 °, 44.6 ° <2θ <45.0 °
And 45.0 ° <2θ <45.4 °.

【0021】[0021]

【表1】 [Table 1]

【0022】[0022]

【表2】 [Table 2]

【0023】表2に示す比較例1〜10で使用した各マ
ンガン酸リチウム粉末のX線回折データをJCPDS−
ICDDデータと照合して、比較例1〜10で使用した
正極活物質が全て斜方晶系マンガン酸リチウムであるこ
とを確認した。
X-ray diffraction data of each of the lithium manganate powders used in Comparative Examples 1 to 10 shown in Table 2 was obtained by JCPDS-
By collating with the ICDD data, it was confirmed that all the positive electrode active materials used in Comparative Examples 1 to 10 were orthorhombic lithium manganate.

【0024】〈各電池の放電容量〉実施例1〜14及び
比較例1〜15で作製した各電池を、電流密度0.15
mA/cm2 で4.3Vまで充電した後、電流密度0.
15mA/cm2 で2.7Vまで放電して、正極活物質
1g当たりの放電容量(mAh/g)を求めた。実施例
1〜14で作製したリチウム二次電池についての結果を
表3に、比較例1〜15で作製したリチウム二次電池に
ついての結果を表4に、それぞれ示す。
<Discharge Capacity of Each Battery> Each of the batteries prepared in Examples 1 to 14 and Comparative Examples 1 to 15 was charged at a current density of 0.15
After charging to 4.3 V at mA / cm 2 , the current density was reduced to 0.4 V.
Discharge was performed at 15 mA / cm 2 to 2.7 V, and the discharge capacity (mAh / g) per 1 g of the positive electrode active material was determined. Table 3 shows the results of the lithium secondary batteries produced in Examples 1 to 14, and Table 4 shows the results of the lithium secondary batteries produced in Comparative Examples 1 to 15.

【0025】[0025]

【表3】 [Table 3]

【0026】[0026]

【表4】 [Table 4]

【0027】表3に示す本発明電池(A1)〜(A1
4)の放電容量は160mAh/g以上であるのに対し
て、表4に示す比較電池(B1)〜(B15)の放電容
量は150mAh/g以下である。この結果から、本発
明により放電容量の大きい、マンガン酸リチウムを正極
活物質とするリチウム二次電池が提供されることが分か
る。また、本発明電池(A2)〜(A5)及び(A9)
〜(A12)の放電容量が特に大きいことから、マンガ
ン酸リチウムとしては、ピークP1 に対するピークP2
のピーク強度比(P2 /P1 )が、0.1〜1.5のも
の、及び、ピークP4 に対するピークP3 のピーク強度
比(P3 /P4 )が、0.1〜1.0のものが好ましい
ことが分かる。
The batteries (A1) to (A1) of the present invention shown in Table 3
While the discharge capacity of 4) is 160 mAh / g or more, the discharge capacities of the comparative batteries (B1) to (B15) shown in Table 4 are 150 mAh / g or less. These results show that the present invention provides a lithium secondary battery having a large discharge capacity and using lithium manganate as a positive electrode active material. Also, the batteries (A2) to (A5) and (A9) of the present invention.
~ Since the discharge capacity is particularly large in (A12), a lithium manganate, the peak P 2 with respect to the peak P 1
Ratio of peak intensities (P 2 / P 1) is one of 0.1 to 1.5, and the peak intensity ratio of the peak P 3 with respect to the peak P 4 (P 3 / P 4 ) is 0.1 to 1 0.0 is preferable.

【0028】〈マンガン酸リチウム粉末の平均粒径(メ
ジアン径)と放電容量の関係〉水酸化リチウムと600
°Cで20時間加熱処理した二酸化マンガン(Mn
2 )とをモル比1:1で混合し、アルゴン雰囲気下に
て、650°Cで12時間加熱処理した後、ジェットミ
ルで粉砕時間を種々変えて粉砕して、メジアン径が1μ
m、3μm、5μm、15μm、20μm又は25μm
の組成式LiMnO2 で表される6種の正極活物質とし
てのマンガン酸リチウム粉末(a15)〜(a20)を
作製した。正極活物質として上記の各マンガン酸リチウ
ム粉末を使用したこと以外は実施例1〜7と同様にし
て、本発明電池(A15)〜(A20)を作製した。次
いで、先述したものと同じ条件の充放電を行って、各電
池の放電容量(mAh/g)を求めた。結果を表5に示
す。表5には、本発明電池(A10)についての結果も
表3より転記して示してある。
<Relationship between average particle diameter (median diameter) of lithium manganate powder and discharge capacity>
Manganese dioxide (Mn) heated at 20 ° C for 20 hours
O 2) and a molar ratio of 1: 1 mixture, under an atmosphere of argon, was 12 hours of heat treatment at 650 ° C, and various varied grinding the grinding time in a jet mill, a median diameter of 1μ
m, 3 μm, 5 μm, 15 μm, 20 μm or 25 μm
The lithium manganate powders (a15) to (a20) as six kinds of positive electrode active materials represented by the composition formula LiMnO 2 were prepared. Batteries (A15) to (A20) of the present invention were produced in the same manner as in Examples 1 to 7, except that each of the above lithium manganate powders was used as the positive electrode active material. Next, the battery was charged and discharged under the same conditions as those described above, and the discharge capacity (mAh / g) of each battery was determined. Table 5 shows the results. Table 5 also shows the results of the battery (A10) of the present invention transcribed from Table 3.

【0029】[0029]

【表5】 [Table 5]

【0030】表5より、正極活物質として使用するマン
ガン酸リチウム粉末としては、メジアン径が5〜20μ
mのものが好ましいことが分かる。
According to Table 5, the lithium manganate powder used as the positive electrode active material has a median diameter of 5 to 20 μm.
It can be seen that m is preferable.

【0031】[0031]

【発明の効果】本発明によれば、放電容量の大きい、マ
ンガン酸リチウムを正極活物質とするリチウム二次電池
が提供される。
According to the present invention, a lithium secondary battery having a large discharge capacity and using lithium manganate as a positive electrode active material is provided.

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

【図1】実施例で作製した扁平形のリチウム二次電池の
断面図である。
FIG. 1 is a cross-sectional view of a flat lithium secondary battery manufactured in an example.

【図2】本発明の実施例で使用したマンガン酸リチウム
のX線回折図である。
FIG. 2 is an X-ray diffraction diagram of lithium manganate used in Examples of the present invention.

【図3】比較例で使用したマンガン酸リチウムのX線回
折図である。
FIG. 3 is an X-ray diffraction diagram of lithium manganate used in a comparative example.

【図4】比較例で使用したマンガン酸リチウムのX線回
折図である。
FIG. 4 is an X-ray diffraction diagram of lithium manganate used in a comparative example.

【符号の説明】[Explanation of symbols]

A リチウム二次電池 1 正極 2 負極 3 セパレータ 4 正極缶 5 負極缶 6 正極集電体 7 負極集電体 8 絶縁パッキング A Lithium secondary battery 1 Positive electrode 2 Negative electrode 3 Separator 4 Positive electrode can 5 Negative electrode can 6 Positive current collector 7 Negative current collector 8 Insulation packing

フロントページの続き (72)発明者 能間 俊之 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 (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 Fターム(参考) 5H003 AA02 BB05 BC01 BD00 BD02 BD03 5H014 AA02 EE10 HH00 HH06 5H029 AJ03 AK03 AL12 AM03 AM07 BJ03 HJ02 HJ05 HJ13 Continued on the front page (72) Inventor Toshiyuki Noma 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Koji Nishio 2-5-2-5 Keihanhondori, Moriguchi-shi, Osaka No. SANYO Electric Co., Ltd. F term (reference) 5H003 AA02 BB05 BC01 BD00 BD02 BD03 5H014 AA02 EE10 HH00 HH06 5H029 AJ03 AK03 AL12 AM03 AM07 BJ03 HJ02 HJ05 HJ13

Claims (4)

【特許請求の範囲】[Claims] 【請求項1】マンガン酸リチウムを正極活物質とするリ
チウム二次電池において、前記マンガン酸リチウムが、
組成式Lix MnOy (xは充放電状態により変動する
値であり、0≦x≦1.2;1.9≦y≦2.1)で表
され、且つx=1の組成のマンガン酸リチウムのCuK
α線を線源として得られるX線回折プロファイルにおい
て、少なくとも、18.2°<2θ<18.6°、2
4.6°<2θ<25.1°、44.6°<2θ<4
5.0°及び45.0°<2θ<45.4°(2θ:回
折角)の4つの範囲に、順に、それぞれピークP1 ,P
2 ,P3 及びP4 を一つずつ有することを特徴とするリ
チウム二次電池。
1. A lithium secondary battery using lithium manganate as a positive electrode active material, wherein the lithium manganate is
Manganese acid having a composition formula Li x MnO y (x is a value that varies depending on the charge / discharge state and is represented by 0 ≦ x ≦ 1.2; 1.9 ≦ y ≦ 2.1) and has a composition of x = 1 Lithium CuK
In an X-ray diffraction profile obtained using an α-ray as a source, at least 18.2 ° <2θ <18.6 °, 2
4.6 ° <2θ <25.1 °, 44.6 ° <2θ <4
Peaks P 1 and P 1 are sequentially assigned to four ranges of 5.0 ° and 45.0 ° <2θ <45.4 ° (2θ: diffraction angle), respectively.
A lithium secondary battery having one of 2 , P 3 and P 4 .
【請求項2】ピークP1 に対するピークP2 のピーク強
度比が、0.1〜1.5である請求項1記載のリチウム
二次電池。
Wherein the peak intensity ratio of the peak P 2 to the peak P 1 is a lithium secondary battery according to claim 1, wherein 0.1 to 1.5.
【請求項3】ピークP4 に対するピークP3 のピーク強
度比が、0.1〜1.0である請求項1記載のリチウム
二次電池。
Wherein the peak intensity ratio of the peak P 3 with respect to the peak P 4 is a lithium secondary battery according to claim 1, wherein 0.1 to 1.0.
【請求項4】前記マンガン酸リチウムが、メジアン径5
〜20μmの粉末である請求項1記載のリチウム二次電
池。
4. The method according to claim 1, wherein the lithium manganate has a median diameter of 5.
The lithium secondary battery according to claim 1, wherein the lithium secondary battery is a powder having a particle size of about 20 m.
JP10202795A 1998-07-01 1998-07-01 Lithium secondary battery Pending JP2000021405A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10202795A JP2000021405A (en) 1998-07-01 1998-07-01 Lithium secondary battery

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10202795A JP2000021405A (en) 1998-07-01 1998-07-01 Lithium secondary battery

Publications (1)

Publication Number Publication Date
JP2000021405A true JP2000021405A (en) 2000-01-21

Family

ID=16463326

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10202795A Pending JP2000021405A (en) 1998-07-01 1998-07-01 Lithium secondary battery

Country Status (1)

Country Link
JP (1) JP2000021405A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008066028A (en) * 2006-09-05 2008-03-21 Nippon Chem Ind Co Ltd Lithium manganate for lithium secondary battery positive electrode secondary active material, and manufacturing method of lithium manganate, lithium secondary battery positive electrode active material, and lithium secondary battery

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008066028A (en) * 2006-09-05 2008-03-21 Nippon Chem Ind Co Ltd Lithium manganate for lithium secondary battery positive electrode secondary active material, and manufacturing method of lithium manganate, lithium secondary battery positive electrode active material, and lithium secondary battery

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