LiNi_xCo_(1-x)O_2合成条件对其结构与性能的影响

Influence of synthetic conditions of LiNi_xCo_(1-x)O_2 on its structure and electrochemical characterisation

研究了在空气下固相合成LiNixCo1-xO2 的工艺及反应预处理方式、不同锂源、温度、时间和配比等因素对产品结构与性能的影响 .结果表明 :采用LiOH为锂源、采取混合研磨后压块以及烘干Ni(OH ) 2 、Co(OH) 2 后加入氢氧化锂的预处理方式更有利于合成反应的进行 ;在 6 0 0℃预烧一段时间的条件下 ,75 0℃恒温合成的产物比 6 5 0℃、85 0℃保温合成的产物层状结构更明显 ,首次充电容量更高 ;在一定范围内 ,随合成时间的增长 ,产物的衍射峰强度增大 ,结构更完整 ,电性能更好 ;按镍钴的不同配比 ,均能合成结构良好的LiNixCo1-xO2 ,而配比为n(Li) :n (Ni) :n (Co) =1.15∶ 0 .3∶ 0 .7时合成的产物初始容量较高 ,达到15 6 .146mAh/g .

To prepare cheaper and better cathode materials for lithium ion battery, LiNi xCo 1-x O 2 (0≤x≤1) was studied and synthesized in solid phase in air. The effect of pretreatment method, lithium resource, synthesis temperature,heat treatment time and ratio of raw materials on the products were discussed. The results show that the use of LiOH as lithium resource and making extrusion molding after mixing and grinding raw and processed materials are beneficial to synthesize the samples. The products preheated at 600 ℃ and then sintered under constant temperature at 750 ℃ is better than those sintered under constant temperature at 650 ℃ or 850 ℃, and their layer feature of structure is more obvious and the initial capacity is higher. The longer the hot treating time, the stronger the intensity of XRD peaks and the better are their structures and electrochemical properties. The samples LiNi xCo 1-x O 2 (0≤x≤1) with good structure and electrochemical performance are synthesized. And initial capacity of the product is perfect when n(Li)∶n(Ni)∶n(Co)=1.15∶ 0.3∶ 0.7, even to 156.146 mAh/g. s