Department of Physics, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
School of Energy and Environment, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China.
ACS Appl Mater Interfaces. 2023 Feb 15;15(6):8046-8053. doi: 10.1021/acsami.2c20405. Epub 2023 Feb 1.
Layered O3-type transition metal oxides are promising cathode candidates for high-energy-density Li-ion batteries. However, the structural instability at the highly delithiated state and low kinetics at the fully lithiated state are arduous challenges to overcome. Here, a facile approach is developed to make secondary particles of Ni-rich materials with nanosheet primary grains. Because the alignment of the primary grains reduces internal stress buildup within the particle during charge-discharge and provides straightforward paths for Li transport, the as-synthesized Ni-rich materials do not undergo cracking upon cycling with higher overall Li ion diffusion rates. Specifically, a LiNiCoMnO cathode with nanosheet grains delivers a high reversible capacity of 206 mAh g and shows ultrahigh cycling stability, e.g., 98% capacity retention over 500 cycles in a full cell with a graphite anode.
层状 O3 型过渡金属氧化物是高能密度锂离子电池有前途的阴极候选材料。然而，在高度去锂化状态下的结构不稳定性和在完全锂化状态下的低动力学是需要克服的艰巨挑战。在这里，开发了一种简便的方法来制备具有纳米片初级晶粒的富镍材料的二次颗粒。由于初级晶粒的排列在充放电过程中减少了颗粒内部的应力积累，并为 Li 传输提供了直接的途径，因此合成的富镍材料在循环过程中不会因更高的整体 Li 离子扩散率而开裂。具体来说，具有纳米片晶粒的 LiNiCoMnO 阴极具有 206 mAh g 的高可逆容量，并表现出超高的循环稳定性，例如，在具有石墨阳极的全电池中经过 500 次循环后，容量保持率为 98%。
