Enhanced cycling performance of surface-doped LiMn2O4 modified by a Li2CuO2-Li2NiO2 solid solution for rechargeable lithium-ion batteries
Enhanced cycling performance of surface-doped LiMn2O4 modified by a Li2CuO2-Li2NiO2 solid solution for rechargeable lithium-ion batteries
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DOI：
10.1016/j.electacta.2016.12.041
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发表时间：
2017-01-10
影响因子：
6.6
通讯作者：
Akiyama, Tomohiro
中科院分区：
文献类型：
--
作者：
Han, Cheng-Gong;Zhu, Chunyu;Akiyama, Tomohiro
使用简单易行的溶胶-凝胶方法合成了一系列由 Li2CuO2-Li2NiO2 固溶体改性的表面掺杂 LiMn2O4 样品，以实现增强的循环性能，特别是在高温下。分别通过X射线衍射（XRD）和扫描电子显微镜（SEM）研究了相应的相结构和形貌。通过 XRD 和透射电子显微镜 (TEM) 证实，LiMn2O4 颗粒表面的改性层具有类 LiNi δ Mn2-δ O4 相以及 Li2CuO2-Li2NiO2 固溶体，在减轻锰溶解方面发挥着关键作用，从而相对于裸 LiMn2O4 提高了循环性能和倍率性能。 0.5 wt.%改性的LiMn2O4样品的放电容量为113 mAh g(-1)，在1C和25℃下循环300次后容量保持率为93.2%，高于裸LiMn2O4的96 mAh g(-1)和81.2%。此外，在 55 摄氏度下，经过 200 次循环后，0.5 wt.% 改性的 LiMn2O4 样品在 1C 时的容量保持率为 81.2%，而裸 LiMn2O4 的容量保持率为 70.0%。通过与 Li2CuO2Li2NiO2 固溶体混合的 LiNi δ Mn2-δ O4 类相对后者的表面进行改性，是改善电化学性能的有效策略。 (C) 2016 年由爱思唯尔有限公司出版。
A series of surface-doped LiMn2O4 samples modified by a Li2CuO2-Li2NiO2 solid solution were synthesized using a simple and facile sol-gel method to achieve the enhanced cycling performance, especially at elevated temperatures. The corresponding phase structure and morphology were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The modified layer on the surface of LiMn2O4 particles, featuring a LiNi delta Mn2-delta O4-like phase, together with a Li2CuO2-Li2NiO2 solid solution, as confirmed by XRD and transmission electron microscopy (TEM), plays a key role in alleviating the dissolution of manganese, thus enhancing the cycling performance and rate capability relative to bare LiMn2O4. The 0.5 wt.%-modified LiMn2O4 sample delivers a discharge capacity of 113 mAh g(-1), and a capacity retention of 93.2% following 300 cycles at 1C and 25 degrees C, which is higher than the values of 96 mAh g(-1) and 81.2% for bare LiMn2O4. In addition, at 55 degrees C, a capacity retention of 81.2% at 1C is obtained for the 0.5 wt.%-modified LiMn2O4 sample after 200 cycles, compared to 70.0% for bare LiMn2O4. Modifying the surface of the latter by a LiNi delta Mn2-delta O4-like phase mixed with a Li2CuO2Li2NiO2 solid solution, is an effective strategy for improving electrochemical properties. (C) 2016 Published by Elsevier Ltd.