为提高锂离子电池正极材料Li[Li0.2Ni0.2Mn0.6]O2的首次充放电效率,对固相法合成的该材料进行了酸浸的改性研究.通过X射线衍射(XRD)、扫描电子显微镜(SEM)对所得样品的结构、形貌进行了表征.结果表明,Li[Li0.2Ni0.2Mn0.6]02经过酸处理后,首次放电效率得到了较大的提高,但是放电中值电压明显下降.其中,0.5 mol·L1的硝酸浸泡5h的效果最佳,首次放电效率达到了86.7％,同时放电容量达到最大值的循环次数大大减少.酸浸改性的原因被归结于材料表面出现了富锂尖晶石结构Li4Mn5O12相.%In order to improve the initial discharge efficiency of Li [Li0.2Ni0.2Mn16]02 as cathode material for rechargeable lithium batteries, Li [Li0.2Ni0.2Mn16]02 synthesized by a solid state method was preconditioned in acids. The product was characterized by XRD and SEM. It is found that the first discharge efficiency of Li[Li0.2Ni0.2Mn0.6 O2 after acid treatment had been greatly improved, but the mid-voltage sharply decreased. The treatment with 0.5 rnol·L-1 HNO3 for 5 h was the best result, the efficiency reached 86.7%, meanwhile, the discharge capacity reached maximum faster than before. The reason of acid leaching modification was attributed to the appearance of the spinel structure Li4MnI5O12 phase with rich lithium.
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