球磨法制备锂金属氮化物及电化学性能研究

采用高能球磨法制备了锂离子电池负极材料锂金属氮化物Li_3-xM_xN(M=Co,Cu等)。制备的锂金属氮化物具有较高的电化学活性和充放电可逆性,可以用作锂离子电池的高容量负极材料。所制备的Li_2.6Co_0.4N前10次循环的脱嵌锂容量高达880mAh·g^-1。Li_2.6Co_0.2Cu_0.2N最初几个循环的脱嵌锂容量为750mAh·g^-1,45次充放电循环后的容量保持率为80％。Li_2.6Co_0.2Fe_0.2N是含有Li_2.6Co_0.4N的两相或多相混合物,40次充放电循环后脱锂容量为560mAh·g^-1,相对第二次脱锂容量的保持率为82％。

Ball-milling Synthesis and Electrochemical Study of Lithium (Transition) Metal Nitrides

Lithium (transition) metal nitrides were synthesized by high-energy ball-milling technique. The obtained samples exhibit high electrochemical activity and reversibility. The average capacity of Li_2.6Co_0.4N samples is ca. 880mAh·g^-1 within the first 10 cycles. Li_2.6Co_0.2Cu_0.2N sample has a capacity about 750mAh·g^-1 after the first several cycles. 80% of its second cycle capacity can be retained at the 45th cycle. Li_2.6Co_0.2Fe_0.2N sample is a mixture of two or more phases including Li_2.6Co_0.4N. It has a capacity about 560 mAh·g^-1 at the 40th cycle, 82% of its second cycle capacity. Good cycling performance suggests that these compounds could be promising anode materials for lithium ion batteries.