摘要
研究了Li Co O2湿法铝氧化物包覆工艺及包覆处理对Li Co O2性能的影响。结果表明:以Al(NO3)3·9H2O为铝源,氨水为溶液p H值缓冲剂,在p H值3.4和7.2的条件下,均可在Li Co O2表面得到铝氧化物包覆层。包覆后的Li Co O2在4.35 V高电压条件下循环120周后,容量保持率为91%左右,而未作处理的Li Co O2在同等条件下的容量保持率仅77.4%,说明通过此包覆工艺处理后Li Co O2在高电压条件下的循环稳定性得到了明显提高。不同p H值条件下所得滤液中钴浓度测定结果表明,酸性条件会造成Li Co O2的大量溶损,虽然Li Co O2在酸性条件下包覆后循环稳定性能得到了提高,但其放电容量会降低。
LiCoO2 coated with aluminum oxide by a wet process, as well as the effect of coating layer on the cycle performance of LiCoO2 were investigated. The results indicate that it is feasible to obtain aluminum oxide coating layer on the surface of LiCoO2 particles in pH=3.4 or pH=7.2, with AI（NO3）3 · 9H2O and ammonia as aluminum source and pH buffering agent, respectively. The capacity retention ratio of LiCoO2 with coatings reaches up to 91% after 120 cycles at high voltage of 4.35 V. As compared, LiCoO2 without coating has only 77.4% capacity retention ratio under the same conditions. It suggested that after LiCoO2 was treated by the coating process, its cycle stability at higher voltage had been obviously improved. The different Co concentration in the filter liquids, obtained from different pH value conditions, indicated that some LiCoO2 was dissolved in acid solution. Although the cycle stability of LiCoO2 after coating has been improved, there would be a drop in its discharge capacity.
出处
《矿冶工程》
CAS
CSCD
北大核心
2015年第5期136-138,142,共4页
Mining and Metallurgical Engineering
