International Joint Research Center for Advanced Energy Materials of Yunnan Province, Electron Microscope Center of Yunnan University, School of Materials and Energy, Yunnan University, 650091, Kunming, China.
Department of Mechanical and Materials Engineering, University of Western Ontario, 1151 Richmond St., N6A3K7, London, Ontario, Canada.
Angew Chem Int Ed Engl. 2023 May 8;62(20):e202300962. doi: 10.1002/anie.202300962. Epub 2023 Apr 7.
Nickel-rich (Ni≥90 %) layered cathodes are critical materials for achieving higher-energy-density and lower-cost next-generation Li-ion batteries (LIBs). However, their bulk and interface structural instabilities significantly impair their electrochemical performance, thus hindering their widespread adoption in commercial LIBs. Exploiting Ti and Mo diffusion chemistry, we report one-step calcination to synthesize bulk-to-surface modified LiNi Co Mo O (NCMo90) featuring a 5 nm Li TiO coating on the surface, a Mo-rich Li /Ni superlattice at the sub-surface, and Ti-doping in the bulk. Such a multi-functional structure effectively maintains its structural integrity upon cycling. As a result, such NCMo90 exhibits a high initial capacity of 221 mAh g at 0.1 C, excellent rate performance (184 mAh g at 5 C), and high capacity retention of 94.0 % after 500 cycles. This work opens a new avenue to developing industry-applicable Ni-rich cathodes for next-generation LIBs.
镍含量丰富（Ni≥90%）的层状阴极材料对于实现更高能量密度和更低成本的下一代锂离子电池（LIBs）至关重要。然而，其体相和界面结构的不稳定性严重影响了其电化学性能，从而阻碍了其在商业 LIBs 中的广泛应用。利用 Ti 和 Mo 的扩散化学，我们通过一步煅烧合成了体相到表面改性的 LiNi Co Mo O（NCMo90），其表面具有 5nm 的 Li TiO 涂层，次表面具有富 Mo 的 Li /Ni 超晶格，体相中有 Ti 掺杂。这种多功能结构在循环过程中能有效地保持其结构完整性。因此，这种 NCMo90 表现出高的初始容量（在 0.1C 时为 221mAh·g），优异的倍率性能（在 5C 时为 184mAh·g），以及在 500 次循环后的 94.0%的高容量保持率。这项工作为开发下一代 LIBs 的工业适用的富镍阴极开辟了一条新途径。
