锂离子电池正极材料尖晶石型LiMn2O4的制备及其掺杂改性

采用固相合成法制备了锂离子电池用尖晶石型LiMn2O4正极材料,并通过同时加入Cr3 和F对材料进行了体相掺杂改性.用扫描电子显微镜和X射线衍射研究了材料的表面形貌和晶体结构,用充放电循环实验对制备的锂离子电池性能进行了测试.结果表明:未掺杂的LiMn2O4正极材料首次放电容量为115.3mAh·g-1,循环25次后容量降为96mAh·g-1;掺杂Cr3 和F的材料同样具有尖晶石型结构,随掺杂量增加,首次放电容量略有降低,但循环性能有较明显改善,充放电效率提高,其中掺杂量为0.10的样品首次放电容量为111.5 mAh·g-1,循环25次后容量保持率达91.8%.

Preparation and Modification of Spinel LiMn2O4 Cathode Material for Li-ion Battery

Spinel LiMn2O4 cathode material for Li-ion battery was prepared by a solid-state reaction,and the material was modified by doping the Cr3+ and F-at the same time.Its morphologies and structure were characterized by scanning electron micrograph and X-ray diffraction,and its electrochemical properties were studied by charge-discharge test.The results show that the 1st and 25th discharging capacity of LiMn2O4 is 115.3 mAh?g-1 and 96 mAh?g-1 respectively.When doping with Cr3+ and F-,the cathode material also has a spinel structure.With the doping level increasing,the initial discharging capacity of material reduces,but its cycling performance and charge-discharge efficiency are greatly improved.When the doping level is 0.1,the sample displays an initial discharging capacity of 111.5mAh?g-1,and its capacity retention after 25 cycles is 91.8%.