大比表面积CoOOH包覆高电压钴酸锂的性能研究

Study on Coating Properties of CoOOH with High Specific Surface Area for High-Voltage LiCoO_(2)

采用液相沉淀-低温热分解法制备了大比表面积羟基氧化钴,通过XRD、SEM和激光粒度仪对样品的结构和形貌进行表征,结果表明所制备的产物主相为CoOOH,其比表面积达到60 m^(2)·g^(-1),形貌呈片状颗粒,中位径D50为0.13μm。同时,研究了大比表面积CoOOH对钴酸锂正极材料的包覆性能及电化学性能。SEM结果表明,大比表面积CoOOH均匀地覆盖在钴酸锂颗粒表面。电性能测试结果表明,CoOOH包覆的钴酸锂在电压3.0—4.6 V范围内经100次循环充放电后,其容量保持率达到87.9%,优于氢氧化钴。

The CoOOH with a high specific surface area was prepared by liquid phase precipitation-thermal decomposition at low temperatures.The structure and morphology of the as-prepared sample were tested by X-Ray diffraction,scanning electron microscopy,and laser particle size analyzer.The results showed that the main phase of the product was CoOOH,whose specific surface area and median diameter D_(50)of the powder were 60 m^(2)∙g^(−1)and 0.13μm,respectively.The coating performance and electrochemical properties of CoOOH with a large specific surface area on LiCoO_(2)were studied,The SEM results displayed that the CoOOH with a large specific surface area was evenly covered on the surface of LiCoO_(2).The electrochemical properties test results showed that the CoOOH-coated LiCoO_(2)had a capacity retention rate of 87.9%after 100 cycles of charging and discharging at a voltage range of 3.0—4.6 V,which is better than that of Co(OH)_(2).