王接喜

博士生闫禹岑论文"Tailoring cobalt gradient distribution toward practical Ni95 cathode for high-energy-density lithium-ion battery"被Joule接收发表

发布时间：2025-11-11

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Improving electric vehicle range and safety is a key focus in new energy research. Ni-rich cathodes (≥200 mA h g-1) are vital for next-generation high-energy Li-ion batteries, but their widespread use in polycrystalline forms is hindered by microcracks, irreversible phase transitions, and lattice oxygen release. This study successfully synthesizes single-crystal, low-cobalt ultrahigh-nickel cathode materials (C-Ni95), which exhibit exceptional cycling stability stemming from an optimized distribution of cobalt element. Particularly, the cobalt surface gradient doping structure plays a crucial role in enhancing the interfacial transport of Li-ions, mitigating volume expansion/contraction, stabilizing the crystal structure, and suppressing harmful parasitic side reactions. Consequently, a high-loading C-Ni95 pouch cell (28.2 mg cm⁻²) retains 85.1% capacity after 800 cycles. Moreover, boron injection further improves performance, achieving 87.1% retention after 2000 cycles. This work offers an effective strategy for the practical synthesis and interfacial modification of high-performance Ni-rich, cobalt-free single-crystal cathodes.