Abstract The high-voltage and low-cost lithium nickel manganese oxides are regarded as the most potential cathode materials for high-density Li-ion batteries (LIBs), but the inferior ionic conductivity and vulnerable lattice oxygen limit their rate and cycle capabilities. Herein, we report a unique pomegranate-like Ti-doped LiNi0.4Mn1.6O4 cathode materials (LNMTO) without surface residues, which are expected to greatly shorten the Li+ transfer distance, enhance reaction kinetics and reduce the electrochemical polarization. Meantime, the strong Ti-O bonds can robust the lattice oxygen and stabilize the crystal structure during electrochemical reactions process. Consequently, the LNMTO exhibits a fast charge-discharge capability with a high reversible capacity of 101 mAh g-1 within 3.5-5.0 V even at 10C with an 84.4 % capacity retention after 500 cycles at 1C, which is superior to the reported LiNi0.4Mn1.6O4-related cathode materials. This work provides a novel inspiration to design and synthesize high-voltage cobalt-free based cathode materials with satisfied lithium storage performances.

中文翻译：

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石榴状Ti掺杂LiNi0.4Mn1.6O4 5 V级正极，具有优异的锂离子电池高压循环和倍率性能

摘要 高电压、低成本的锂镍锰氧化物被认为是高密度锂离子电池（LIBs）最有潜力的正极材料，但离子电导率差和晶格氧脆弱，限制了其倍率和循环能力。在此，我们报告了一种独特的石榴状 Ti 掺杂 LiNi0.4Mn1.6O4 正极材料（LNMTO），没有表面残留物，有望大大缩短 Li+ 转移距离，增强反应动力学并降低电化学极化。同时，强的 Ti-O 键可以在电化学反应过程中增强晶格氧并稳定晶体结构。因此，LNMTO 在 3.5-5.0 V 范围内表现出快速充放电能力，具有 101 mAh g-1 的高可逆容量，即使在 10C 下也具有 84。在 1C 下循环 500 次后容量保持率为 4%，优于报道的 LiNi0.4Mn1.6O4 相关正极材料。这项工作为设计和合成具有满意锂存储性能的高压无钴基正极材料提供了新的灵感。