LiNi_(0.8)Co_(0.2-2x)Al_xMn_xO_2材料的制备与电化学储能性能

Preparation and Electrochemical Energy Storage Performances of LiNi_(0.8)Co_(0.2-2x)Al_xMn_xO_2 Cathode Material

采用高温固相法制备了LiNi_(0.8)Co_(0.2-2x)Al_xMn_xO_2(x=0,0.005,0.01,0.025,0.04,0.05)系列材料,并对材料的形貌、结构和电化学性能等进行了表征.研究结果表明,所得材料均具有α-NaFeO_2结构,阳离子混排程度随着锰、铝元素的增加和钴元素的减少呈现先减小后增加的趋势.当x=0.01时,材料的锂镍混排程度最低,拥有最小的电荷转移阻抗和较大的锂离子扩散系数,电化学性能和稳定性最好.在0.1C下,放电比容量可达175.2 mA·h/g;在0.2C下,循环50周后容量保持率为92.7%.

A series of LiNi（0.8）Co（0.2-2x）AlxMnxO2（x = 0,0. 005,0. 01,0. 025,0. 04,0. 05） materials was prepared by high temperature solid phase method. The morphology, structures and electrochemical performances of the materials were characterized. The results showed that all the obtained materials hadα-NaFeO2 structure and the degree of lithium nickel cation mixing decreased first and then increased with the increase of manganese,aluminum elements along with cobalt element decreasing. When x was equal to 0. 01,the material had the lowest degree of lithium nickel cation mixing,the smallest charge transfer impedance and larger lithium ion diffusion coefficient. And the material exhibited the best electrochemical performances and stability among the obtained materials： its discharge capacity was up to 175. 2 mA·h/g at 0. 1 C; the capacity retention rate was up to 92. 7% after 50 cycles at 0. 2 C.