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STUDIES ON MODIFICATION OF LITHIUM MANGANATE PARTICLE SURFACE FOR LITHIUM ION BATTERY WITH METAL OXIDE

金属氧化物对锂离子电池锰酸锂颗粒表面改性的研究

基本信息

批准号：
10650828
负责人：
TORI Isao
金额：
$ 1.92万
依托单位：
OKAYAMA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650828/
关键词：
Lithium manganate Cycling characteristics Modification リチウム電池

项目摘要

In order to remarkably improve the charge-discharge cycling characteristics at temperatures above 50ィイD1゜ィエD1C of LiMnィイD22ィエD2OィイD24ィエD2 as a positive electrodematerial of lithium ion battery, the oxide was partially modified with cobalt (III) oxide at the particle surface. The method for the modification was as follows : dispersing electrolytic manganese dioxide powder (EMD) in aqueous solution of cobalt (II) nitrate, adding sodium hydroxide solution to it to prepare the powder coated with cobalt hydroxide which was oxidized by oxygen in air, separating the powder from the solution, mixing lithium compounds and the powder at the ratio of (Mn+Co) : Li=2 : 1 and then heating the mixture at 470ィイD1゜ィエD1C for 6h, followed by further heating at 750ィイD1゜ィエD1C for 20h to prepare LiCoィイD2yィエD2MnィイD22-yィエD2OィイD24ィエD2 (y=0.04, 0.08, and 0.16). The samples obtained were confirmed to have spinel structure by XRD and a large part of cobalt (III) ions were found to exist preferentially at the powd … More er surface by EDX analysis. Small amount of the ions were thought to be in the inner part of the particles in dilute concentration due to thermal diffusion of the ions. The samples of LiCoィイD2yィエD2MnィイD22-yィエD2OィイD24ィエD2 were tested on the charge-discharge cycling characteristics at 30 and 60ィイD1゜ィエD1C. Comparison of the characteristics at 30ィイD1゜ィエD1C showed that modification yielded remarkably improved charge-discharge performance, though that of LiMnィイD22ィエD2OィイD24ィエD2 did such a performance that discharge capacity considerably decreased with charge-discharge cycling. But the characteristics at 60ィイD1゜ィエD1C showed that even the modified samples did not provide good performance. In order to change the distribution of cobalt ion in the oxides, LiCoィイD2yィエD2MnィイD22-yィエD2OィイD24ィエD2 samples were heated at 900ィイD1゜ィエD1C for 30m. The samples obtained also did not provide good performance. As a further experiment the surface of EMD was treated using ferrous ion, nickel ion and magnesium ion instead of cobalt ion, and lithium manganate powders including these ions were synthesized. As a result of examining the charge-discharge cycling characteristics of LiMィイD20ィエD2MnィイD21・84ィエD2OィイD24ィエD2 (M=Fe, Ni, Mg) at 60ィイD1゜ィエD1C LiNiィイD20・16ィエD2MnィイD21・84ィエD2OィイD24ィエD2 provided an excellent characteristics. It was found that modification of LiMnィイD22ィエD2OィイD24ィエD2 powder with nickel oxide at the particle surface remarkably improves the charge-discharge cycling characteristics at higher temperature. Less

为了显著改善锂离子电池正极材料LiMn氧化物D22氧化物D20氧化物D24氧化物D2在50 ℃以上的充放电循环特性，在其颗粒表面用氧化钴（III）部分改性。改性方法为：将电解二氧化锰粉末（EMD）分散在硝酸钴（II）水溶液中，加入氢氧化钠溶液，制备包覆有氢氧化钴的粉末，在空气中用氧气氧化，将粉末与溶液分离，将锂化合物与粉末以（Mn+Co）：Li=2：1的比例混合。1，然后将混合物在470 ℃ D1下加热6 h，接着在750 ℃ D1下进一步加热20 h，以制备LiCo双金属D2 y双金属D2 Mn双金属D22-y双金属D2 O双金属D24双金属D2（y=0.04、0.08和0.16）。XRD分析表明，样品具有尖晶石结构，且大部分钴离子优先存在于粉体中， ...更多信息通过EDX分析，少量的离子被认为是由于离子的热扩散而以稀浓度存在于颗粒的内部。测试了LiCo双金属D2 y双金属D2 Mn双金属D22-y双金属D2 O双金属D24双金属D2样品在30和60 ℃下的充放电循环特性。在30 ℃下的特性比较表明，改性产生了显着改善的充电-放电性能，虽然LiMn掺杂D22的D24的D22的D20的D24的D24的D24的D22的性能，放电容量显着下降的充放电循环。但是在60 ° C下的特性表明，即使是改性的样品也没有提供良好的性能。为了改变钴离子在氧化物中的分布，将LiCo_（22-y）Co_（24）在900 ℃下加热30分钟。获得的样本也没有提供良好的性能。作为进一步的实验，用亚铁离子、镍离子和镁离子代替钴离子对EMD进行表面处理，合成了含有这些离子的锂离子电池粉末。作为在60 ℃下检查LiM锂离子D20锂离子D2 Mn锂离子D21·84锂离子D2 O锂离子D24锂离子D2（M=Fe、Ni、Mg）的充放电循环特性的结果，LiNi锂离子D20·16锂离子D2 Mn锂离子D21·84锂离子D2 O锂离子D24锂离子D2提供了优异的特性。结果表明，在LiMn_（22）O_（24少