High tap-density and high performance LiFePO4/C cathode material synthesized by the combined sol spray-drying and liquid nitrogen quenching method
High tap-density and high performance LiFePO4/C cathode material synthesized by the combined sol spray-drying and liquid nitrogen quenching method
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DOI：
10.1016/j.matlet.2012.08.076
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发表时间：
2012-12
影响因子：
3
通讯作者：
Ling Wu;Shengkui Zhong;Jie-qun Liu;Fan Lv;K. Wan
中科院分区：
文献类型：
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作者：
Ling Wu;Shengkui Zhong;Jie-qun Liu;Fan Lv;K. Wan
采用溶胶喷雾干燥和液氮淬火相结合的方法合成了正极材料LiFePO4/C。结合了Sol-Gel、喷雾干燥和淬火的优点，结晶良好的LiFePO4/C样品既具有较高的敲击密度，又具有优异的电化学性能。球状颗粒的尺寸为0.1-6μm，振子密度高达1.53gcm−3。透射电子显微镜结果表明，LiFePO4晶体中存在大量的缺陷，并且在其表面存在一层均匀的碳层(∼2 nm)。电化学测试表明，淬火可以显著改善LiFePO4/C的倍率性能和循环性能。淬火样品在0.1C、1C和10C倍率下的首次放电容量分别为162.5、154.7和117.8mAhg−1，在不同倍率下循环110次后，当倍率恢复到0.1C时，容量可以恢复到原值的99.4%。
The cathode material LiFePO4/C is synthesized by a combined sol spray-drying and liquid nitrogen quenching method. Combining the advantages of sol–gel, spray-drying, and quenching, the well crystallized LiFePO4/C sample possesses both high tap-density and excellent electrochemical performance. The sphere-like particles are of the size 0.1–6μm, and the tap-density is as high as 1.53gcm−3. TEM results show that there are a number of defects in LiFePO4crystals, and a uniform carbon layer (∼2nm) exists on the LiFePO4grain surface. Electrochemical tests reveal that quenching can greatly improve the rate capability and cycle performance of LiFePO4/C. The quenched sample shows the initial discharge capacities of 162.5, 154.7 and 117.8mAhg−1at 0.1C, 1C and 10C rate, respectively, and after the cell cycled 110 times at different rates, the capacity can recover to 99.4% of its original value when the rate reverses back to 0.1C.