【摘要】 采用高温固相熔融加压法合成LiNiO₂正极材料,研究了助熔剂LiNO₃的加入量和反应体系中O₂压力对材料的结构和放电容量的影响．结果表明,随着LiNO₃加入量的增加,产物容量先增加后减小,LiOH和LiNO₃摩尔比0．9:0．1时产物结构和容量性能最佳;增大反应体系中O₂压力,产物结构和放电容量均得到改善．对LiNiO₂进行循环性能检测,30次循环后放电容量保持率为81．8%,晶型保持很好,相变反应特征变得明显,但是充电平台电位降低．采用交流阻抗技术计算知Li⁺在Li_xNiO₂活性材料中的扩散系数在10^-9cm²s^-1数量级,扩散系数较大,因而在充放电过程中Li⁺迁移扩散更容易,材料电化学活性提高．更多还原

【Abstract】 LiNiO₂ cathod material was prepared through high-temperature solid-state melting pressuring method.The effects of LiNO₃ addition and O₂ pressure in reaction system on the structures and the discharge capacities of LiNiO₂ products were investigated.The results showed that with the increasing of LiNO₃ addition,discharge capacities of LiNiO₂ products increased at first and then decreased.When the molar ratio of LiOH and LiNO₃ is 0.9:0.1,the structure and discharge capacity are optimal.With the increasing of O₂ pressure,structure and discharge capacity of LiNiO₂ products were improved.Capacity conservation rate of LiNiO₂ after 30 cycles is 81.8%,structure is keeped very well,phase transformations are obvious,but the flat voltage in charge process decreased.Diffusion coefficients of Li⁺ in Li_xNiO₂ calculated through AC method are at 10^-9cm²s^-1 order,they are upper,which indicates that the transfer and diffusion of Li⁺ are easier during charge-discharge process,the electrochemical activity of material increases.更多还原