钠离子电池Cu基正极材料的研究

Study on Cu-based Cathode Material for Sodium-ion Battery

钠离子电池O3型NiFeMn(NFM111)基层状氧化物正极材料因具有优异的容量而被广泛研究,但材料的空气稳定性及成本问题也限制了其产业化的进程。本项工作中,通过引入廉价的Cu元素替代部分Ni元素,不仅降低了成本,还实现了材料的高空气稳定性。材料的结构表征主要通过XRD、SEM来研究,材料的残碱数据主要通过化学分析来研究。试验结果表明,Cu基正极材料(Na_(0.98)Cu_(0.11) Ni_(0.22) Fe_(0.33) Mn_(0.34)O_(2),CNFM)具有极低的表面残碱(Na_(2)CO_(3):2579μg/g,NaOH:108μg/g)和优异的电化学性能,0.1 C充放电克容量分别为135.29、127.24 mAh/g,首次效率高达94.05%,且在1 C的电流密度下容量高达118.84 mAh/g,循环50周后容量保持率高达93.98%。

The O3-layered oxide of sodium ion battery cathode material,based on NiFeMn(NFM111)has been widely studied because of its excellent capacity,but the air stability and cost issues limit its industrialization process.In this work,the above problems have solved through a simple method by introducing Cu(cheap element)to replace part of Ni.The structural characterization of the materials is studied by XRD and SEM,and the residual alkaline substances is studied by chemical analysis.The results revealed that Cu-based cathode material(Na_(0.98)Cu_(0.11) Ni_(0.22) Fe_(0.33) Mn_(0.34)O_(2),CNFM)has a low content of surface residual alkaline substances(Na_(2)CO_(3):2579 ppm,NaOH:108 ppm)and excellent electrochemical properties.The charge and discharge specific capacities are 135.29 and 127.24 mAh/g at the current density of 0.1C,respectively,with an initial efficiency of 94.05%.Moreover,the discharge specific is up to 118.84 mAh/g at a current density of 1C,with a 93.98%capacity retention after 50 cycles.