Faculty of Applied Chemical Engineering, Chonnam National University, Gwang-ju 500-757 (Korea).
ChemSusChem. 2014 Mar;7(3):829-34. doi: 10.1002/cssc.201301037. Epub 2014 Jan 7.
Extraordinary performance at elevated temperature is achieved for high-voltage spinel-phase LiNi0.5 Mn1.5 O4 cathodes prepared using an adipic-acid-assisted sol-gel technique and doped with vanadium. V-substitution in the Li sites (Wykoff position 8a) is confirmed by V K-edge X-ray absorption spectroscopy and Rietveld refinement (Li0.995 V0.005 Ni0.5 Mn1.5 O4 ). V-doped LiNi0.5 Mn1.5 O4 delivered a reversible capacity of approximately 130 and 142 mAh g(-1) at ambient and elevated temperature conditions, respectively. Furthermore, the Li0.995 V0.005 Ni0.5 Mn1.5 O4 phase rendered approximately 94 % and 84 % of initial capacity compared to approximately 85 % and 3 % for the LiNi0.5 Mn1.5 O4 phase after 100 cycles in ambient and elevated temperature conditions, respectively. The enhancements are mainly because of the suppression of Mn dissolution and unwanted side reaction with electrolyte counterpart, and to the increase in conductivity, improving the electrochemical profiles for the V-doped phase.
采用己二酸辅助溶胶-凝胶技术制备并掺杂钒的高压尖晶石相 LiNi0.5 Mn1.5 O4 正极，在高温下表现出优异的性能。钒取代 Li 位（Wykoff 位置 8a）通过 V K 边 X 射线吸收光谱和 Rietveld 精修（Li0.995 V0.005 Ni0.5 Mn1.5 O4）得到证实。掺杂钒的 LiNi0.5 Mn1.5 O4 在环境温度和高温条件下分别提供了约 130 和 142 mAh g-1 的可逆容量。此外，与 LiNi0.5 Mn1.5 O4 相比，Li0.995 V0.005 Ni0.5 Mn1.5 O4 在环境温度和高温条件下循环 100 次后，分别保持了约 94%和 84%的初始容量，而保持了约 85%和 3%的初始容量。这些改进主要是由于抑制了 Mn 的溶解和与电解液的副反应，以及电导率的提高，改善了掺杂钒相的电化学性能。
