Cobalt-substituted Na0.44Mn1-xCoxO2: phase evolution and a high capacity positive electrode for sodium-ion batteries
Cobalt-substituted Na0.44Mn1-xCoxO2: phase evolution and a high capacity positive electrode for sodium-ion batteries
复制标题
DOI：
10.1016/j.electacta.2016.07.089
复制
发表时间：
2016-09
影响因子：
6.6
通讯作者：
Yu-Ting Zhou;Xin Sun;Bangkun Zou;Jia-Yin Liao;Z. Wen;Chun-hua Chen
中科院分区：
文献类型：
--
作者：
Yu-Ting Zhou;Xin Sun;Bangkun Zou;Jia-Yin Liao;Z. Wen;Chun-hua Chen
采用热聚合法制备了Na0.44Mn1-xCoxO2（x = 0,0.01, 0.08, 0.11, 0.22, 0.33, 0.44）粉体作为钠离子电池正极。用x射线衍射和扫描电子显微镜分析了它们的晶体结构和颗粒形态。恒流电池循环用来表征电化学性能。共取代可使na0.44 mn1 - xcoxo2的结构由t型（x = 0）转变为层状p2型（x = 0.11）或p3型（x = 0.44）。对于我们特定条件下合成的样品，颗粒形态可以作为其晶体结构的指标：棒状（t型），片状（p2型）和颗粒状（p3型）。p2型na0.44 mn0.89 co0.11 o20允许更多的Na+插入到层间间距中，并且在2.0-4.2 V电压范围内，在初始周期为12 mA g - 1时具有220 mAh g - 1的高放电容量，在40次循环后具有180 mAh g - 1，在2.0-4.0 V电压范围内，在600 mA g - 1的速率下具有104 mAh g - 1的良好倍率性能。
Na0.44Mn1-xCoxO2(x = 0, 0.01, 0.08, 0.11, 0.22, 0.33, 0.44) powders are synthesized as positive electrodes for sodium-ion batteries via a thermopolymerization method. X-ray diffraction and scanning electron microscopy are used to analyze their crystal structures and particle morphologies. Galvanostatic cell cycling is used to characterize the electrochemical properties. The Co-substitution can change the structure of Na0.44Mn1-xCoxO2from T-type (x = 0) into layered P2-type (x = 0.11) or P3-type (x = 0.44). For the samples synthesized under our specific conditions, the particle morphology can be used as an indicator of their crystal structures: rod-like (T-type), plate-like (P2-type) and granules (P3-type). P2-type Na0.44Mn0.89Co0.11O2allows more Na+intercalation into the inter-layer spacing and results in a high discharge capacity with 220 mAh g−1at 12 mA g−1in initial cycle, 180 mAh g−1after 40 cycles in the voltage range of 2.0-4.2 V and a good rate performance of 104 mAh g−1at a rate of 600 mA g−1in the voltage range of 2.0-4.0 V.