Manganese-based materials have been widely recognized as the most promising cathode materials for aqueous zinc-ion batteries (ZIBs). However, due to the problems of disproportionation reaction and slow electron transport, the development of manganese-based materials is greatly limited. In this work, a carbon-coated Ni-doped ZnMnO quantum dot (NZMO QD@C) were obtained by a combined strategy of gradient calcination and electrochemical induction process with Mn-MIL-100 as the precursor. The presence of 0D quantum dot structure allows ZnMnO to have shorter Zn diffusion pathways and more active sites. Meanwhile, the doping of Ni can promote electron rearrangement, improve conductivity, and ultimately improve the reaction kinetics and electrochemical performance of cathode materials. Furthermore, Ni doping can effectively enhance the stability of the Mn-O bond in NZMO QD@C by optimizing the Mn ion state and electronic bandgap. Therefore, the synthesized NZMO QD@C provide a higher specific capacity of 392 mAh g (0.1 A g) and better (≈80.28 % capacity retention for more than 820 cycles at 1 A g) than original MO QD@C cathode. This work brings new ideas to promote the development and design of manganese-based oxide cathode materials for ZIBs.

中文翻译：

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Ni掺杂和原位电化学诱导协同提高ZnMn2O4量子点的储锌性能


锰基材料被广泛认为是水系锌离子电池（ZIB）最有前途的正极材料。然而，由于歧化反应和电子传输缓慢等问题，锰基材料的发展受到很大限制。本工作以Mn-MIL-100为前驱体，通过梯度煅烧和电化学诱导过程相结合的策略获得了碳包覆的Ni掺杂ZnMnO量子点（NZMO QD@C）。 0D量子点结构的存在使得ZnMnO具有更短的Zn扩散路径和更多的活性位点。同时，Ni的掺杂可以促进电子重排，提高电导率，最终改善正极材料的反应动力学和电化学性能。此外，Ni掺杂可以通过优化Mn离子态和电子带隙，有效增强NZMO QD@C中Mn-O键的稳定性。因此，合成的 NZMO QD@C 提供了 392 mAh g（0.1 A g）的更高比容量，并且比原始 MO QD@C 正极更好（1 A g-1 下超过 820 个循环，容量保持率约为 80.28%）。这项工作为促进ZIBs锰基氧化物正极材料的开发和设计带来了新的思路。