Wang Tianshuo, Zhang Chunxiao, Li Shuwei, Shen Xi, Zhou Liangjun, Huang Qun, Liang Chaoping, Wang Zhaoxiang, Wang Xuefeng, Wei Weifeng
State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083, China.
School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100190, China.
ACS Appl Mater Interfaces. 2021 Mar 17;13(10):12159-12168. doi: 10.1021/acsami.1c01351. Epub 2021 Mar 5.
Lithium-rich manganese-based layered oxide cathodes (LLOs) with oxygen redox reactions are considered to be potential candidates for the next generation of high-energy-density Li-ion batteries. However, the oxygen redox process that enables ultrahigh specific capacity usually leads to irreversible O release and cation migration, which induce structure degradation and severe capacity/voltage losses and thus limit the commercial application of LLOs. Herein, we successfully synthesized chlorine (Cl)-doped Co-free LLOs (LiMnNiOCl) and analyzed the effect of anion doping on oxygen redox and structure stability of LLOs. Cl doping has been proven to decrease the irreversible lattice oxygen loss to enhance the redox reversibility of oxygen and inhibit the transition-metal migration during cycles, which substantially enhances the capacity and voltage retention and improves the rate capability during cycling. This work provides new insights for the development of high-performance TM oxide cathode materials with reversible oxygen redox.
具有氧氧化还原反应的富锂锰基层状氧化物阴极（LLOs）被认为是下一代高能量密度锂离子电池的潜在候选材料。然而，能够实现超高比容量的氧氧化还原过程通常会导致不可逆的氧释放和阳离子迁移，从而引起结构退化以及严重的容量/电压损失，进而限制了LLOs的商业应用。在此，我们成功合成了氯（Cl）掺杂的无钴LLOs（LiMnNiOCl），并分析了阴离子掺杂对LLOs的氧氧化还原和结构稳定性的影响。已证明Cl掺杂可减少不可逆的晶格氧损失，以增强氧的氧化还原可逆性，并抑制循环过程中的过渡金属迁移，这显著提高了容量和电压保持率，并改善了循环过程中的倍率性能。这项工作为开发具有可逆氧氧化还原的高性能过渡金属氧化物阴极材料提供了新的见解。
