Beijing Key Laboratory of Theory and Technology for Advanced Batteries Materials, College of Engineering, Peking University, Beijing, 100871, P. R. China.
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui, 230026, P. R. China.
Adv Mater. 2018 Apr;30(16):e1707255. doi: 10.1002/adma.201707255. Epub 2018 Mar 13.
A high capacity cathode is the key to the realization of high-energy-density lithium-ion batteries. The anionic oxygen redox induced by activation of the Li MnO domain has previously afforded an O3-type layered Li-rich material used as the cathode for lithium-ion batteries with a notably high capacity of 250-300 mAh g . However, its practical application in lithium-ion batteries has been limited due to electrodes made from this material suffering severe voltage fading and capacity decay during cycling. Here, it is shown that an O2-type Li-rich material with a single-layer Li MnO superstructure can deliver an extraordinary reversible capacity of 400 mAh g (energy density: ≈1360 Wh kg ). The activation of a single-layer Li MnO enables stable anionic oxygen redox reactions and leads to a highly reversible charge-discharge cycle. Understanding the high performance will further the development of high-capacity cathode materials that utilize anionic oxygen redox processes.
高容量阴极是实现高能量密度锂离子电池的关键。先前通过激活 LiMnO 畴来诱导阴离子氧氧化还原反应，提供了一种 O3 型层状富锂材料，可用作锂离子电池的阴极，具有显著的高容量 250-300mAh/g。然而，由于由这种材料制成的电极在循环过程中严重的电压衰减和容量衰减，其在锂离子电池中的实际应用受到限制。本文表明，具有单层 LiMnO 超结构的 O2 型富锂材料可以提供非凡的可逆容量 400mAh/g（能量密度：≈1360Wh/kg）。单层 LiMnO 的激活可以实现稳定的阴离子氧氧化还原反应，并导致高度可逆的充放电循环。对这种高性能的理解将进一步推动利用阴离子氧氧化还原过程的高容量阴极材料的发展。
