通过简易的无焰燃烧法合成了LiMn2O4、LiNi0.08Mn1.92O4和LiNi0.08Cu0.05Mn1.87O43种正极材料。利用XRD、SEM、恒电流充放电测试等手段对合成材料的结构、形貌和电化学性能进行了表征。结果表明,所制备的3种正极材料均为立方尖晶石结构;...通过简易的无焰燃烧法合成了LiMn2O4、LiNi0.08Mn1.92O4和LiNi0.08Cu0.05Mn1.87O43种正极材料。利用XRD、SEM、恒电流充放电测试等手段对合成材料的结构、形貌和电化学性能进行了表征。结果表明,所制备的3种正极材料均为立方尖晶石结构;Ni-Cu共掺杂提高了LiNi0.08Cu0.05Mn1.87O4材料的晶体结构稳定性,表现出比LiNi0.08Mn1.92O4和LiMn2O4材料较好的倍率性能和循环寿命。在室温和1 C倍率下,LiNi0.08Cu0.05Mn1.87O4样品的首次比容量为104.7 m A·h/g,循环200次后的容量保持率为81.38%;在较高的倍率5 C循环1000次后,容量保持率为68.23%;即使在高温55℃和1 C倍率下,仍可获得较高的首次放电比容量,为110.8 m A·h/g,200次循环后的容量保持率为56.23%。CV和EIS测试结果表明,LiNi0.08Cu0.05Mn1.87O4具有较好的循环可逆性和较小的电荷转移阻抗。展开更多
LiNi0. 45 Co0. 10 Mn0. 4sO2 was synthesized from Li2CO3 and a triple oxide of nickel, cobalt and manganese at 950 ℃ in air. The structures and characteristics of LiNi0. 45 Co0.10 Mn0. 45 O2, LiCoO2 and LiMn2 O4 were ...LiNi0. 45 Co0. 10 Mn0. 4sO2 was synthesized from Li2CO3 and a triple oxide of nickel, cobalt and manganese at 950 ℃ in air. The structures and characteristics of LiNi0. 45 Co0.10 Mn0. 45 O2, LiCoO2 and LiMn2 O4 were investigated by XRD, SEM and electrochemical measurements. The results show that LiNi0.4s Co0.10 Mn0. 45 O2 has a layered structure with hexagonal lattice. The commercial LicoO2 has sphere-like appearance and smooth surfaces, while the LiMn2 O4 and LiNi0.45 Co0. 10 Mn0. 45 O2 consist of cornered and uneven particles. LiNi0. 45 Co0.10 Mn0. 45 O2 has a large disLiMn2 O4 and LiCoO2, respectively. LiCoO2 and LiMn2 O4 have higher discharge voltage and better rate-capability than LiNi0. 45Co0.10 Mn0. 45 O2. All the three cathodes have excellent cycling performance with capacity retention of above 89.3 % at the 250th cycle. Batteries with LiMn2 O4 or LiNi0.45 Co0.10 Mn0. 45 O2 cathodes show better safety performance under abusive conditions than those with LiCoO2 cathodes.展开更多
文摘通过简易的无焰燃烧法合成了LiMn2O4、LiNi0.08Mn1.92O4和LiNi0.08Cu0.05Mn1.87O43种正极材料。利用XRD、SEM、恒电流充放电测试等手段对合成材料的结构、形貌和电化学性能进行了表征。结果表明,所制备的3种正极材料均为立方尖晶石结构;Ni-Cu共掺杂提高了LiNi0.08Cu0.05Mn1.87O4材料的晶体结构稳定性,表现出比LiNi0.08Mn1.92O4和LiMn2O4材料较好的倍率性能和循环寿命。在室温和1 C倍率下,LiNi0.08Cu0.05Mn1.87O4样品的首次比容量为104.7 m A·h/g,循环200次后的容量保持率为81.38%;在较高的倍率5 C循环1000次后,容量保持率为68.23%;即使在高温55℃和1 C倍率下,仍可获得较高的首次放电比容量,为110.8 m A·h/g,200次循环后的容量保持率为56.23%。CV和EIS测试结果表明,LiNi0.08Cu0.05Mn1.87O4具有较好的循环可逆性和较小的电荷转移阻抗。
基金Project(50302016) supported by the National Natural Science Foundation of China Project(2005037698) supported by the Postdoctoral Science Foundation of China
文摘LiNi0. 45 Co0. 10 Mn0. 4sO2 was synthesized from Li2CO3 and a triple oxide of nickel, cobalt and manganese at 950 ℃ in air. The structures and characteristics of LiNi0. 45 Co0.10 Mn0. 45 O2, LiCoO2 and LiMn2 O4 were investigated by XRD, SEM and electrochemical measurements. The results show that LiNi0.4s Co0.10 Mn0. 45 O2 has a layered structure with hexagonal lattice. The commercial LicoO2 has sphere-like appearance and smooth surfaces, while the LiMn2 O4 and LiNi0.45 Co0. 10 Mn0. 45 O2 consist of cornered and uneven particles. LiNi0. 45 Co0.10 Mn0. 45 O2 has a large disLiMn2 O4 and LiCoO2, respectively. LiCoO2 and LiMn2 O4 have higher discharge voltage and better rate-capability than LiNi0. 45Co0.10 Mn0. 45 O2. All the three cathodes have excellent cycling performance with capacity retention of above 89.3 % at the 250th cycle. Batteries with LiMn2 O4 or LiNi0.45 Co0.10 Mn0. 45 O2 cathodes show better safety performance under abusive conditions than those with LiCoO2 cathodes.
