Yang Yali, Gao Chuan, Luo Tie, Song Jin, Yang Tonghuan, Wang Hangchao, Zhang Kun, Zuo Yuxuan, Xiao Wukun, Jiang Zewen, Chen Tao, Xia Dingguo
Beijing Key Laboratory of Theory and Technology for Advanced Batteries Materials, School of Materials Science and Engineering, Peking University, Beijing, 100871, P. R. China.
Institute of Carbon Neutrality, Peking University, Beijing, 100871, P. R. China.
Adv Mater. 2023 Dec;35(52):e2307138. doi: 10.1002/adma.202307138. Epub 2023 Nov 20.
Lithium-rich Mn-based oxides have gained significant attention worldwide as potential cathode materials for the next generation of high-energy density lithium-ion batteries. Nonetheless, the inferior rate capability and voltage decay issues present formidable challenges. Here, a Li-rich material equipped with quasi-three-dimensional (quasi-3D) Li-ion diffusion channels is initially synthesized by introducing twin structures with high Li-ion diffusion coefficients into the crystal and constructing a "bridge" between different Li-ion diffusion tunnels. The as-prepared material exhibits monodispersed micron-sized primary particles (MP), delivering a specific capacity of 303 mAh g at 0.1 C and an impressive capacity of 253 mAh g at 1 C. More importantly, the twin structure also serves as a "breakwater" to inhibit the migration of Mn ions and improve the overall structural stability, leading to cycling stability with 85% capacity retention at 1 C after 200 cycles. The proposed strategy of constructing quasi-3D channels in the layered Li-rich cathodes will open up new avenues for the research and development of other layered oxide cathodes, with potential applications in industry.
富锂锰基氧化物作为下一代高能量密度锂离子电池的潜在阴极材料，在全球范围内受到了广泛关注。然而，其较差的倍率性能和电压衰减问题带来了巨大挑战。在此，通过将具有高锂离子扩散系数的孪晶结构引入晶体，并在不同的锂离子扩散通道之间构建“桥梁”，首次合成了一种具有准三维（准3D）锂离子扩散通道的富锂材料。所制备的材料呈现出单分散的微米级一次颗粒（MP），在0.1 C下的比容量为303 mAh g，在1 C下的容量高达253 mAh g，令人印象深刻。更重要的是，孪晶结构还起到了“防波堤”的作用，抑制了锰离子的迁移，提高了整体结构稳定性，使得在1 C下循环200次后容量保持率达到85%，展现出良好的循环稳定性。在层状富锂阴极中构建准3D通道的策略将为其他层状氧化物阴极的研发开辟新途径，并具有潜在的工业应用价值。
