Zhou Yuncheng, Xu Yuxing, Song Jiechen, Tan Qiangqiang
State Key Laboratory of Mesoscience and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China.
School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
ACS Appl Mater Interfaces. 2024 Oct 2;16(39):52539-52549. doi: 10.1021/acsami.4c12757. Epub 2024 Sep 18.
Mn-based cation disordered rock-salt (DRX) cathode materials exhibit promising application prospects due to their cost-effectiveness and high specific capacity. However, the synthesis methods commonly employed for these materials rely on the solid-state reaction method and mechanochemistry method, primarily attributed to the influence of low-valence states of Mn. Currently, sol-gel approaches for preparing Mn-based DRX cathode materials are limited to systems involving Mn. Furthermore, there is a paucity of research regarding the modification of Mn-based DRX. To address this concern, the submicrometer-sized carbon-coated LiMnTiO/C materials were synthesized via a one-step sintering process using the sol-gel method with sucrose as the carbon source, resulting in smaller particle sizes compared to those prepared by the solid-state reaction at the same temperature. When employed as a cathode material for lithium batteries, samples prepared with 10 wt % sucrose exhibited exceptional cycling stability by delivering an initial discharge specific capacity of 119.6 mA h g (at a current density of 20 mA g). After 20 charge-discharge cycles, a reversible specific capacity of 91.0 mA h g was achieved, with a capacity retention rate of 76.1%. This approach provides distinctive insights and strategies for the preparation and modification of manganese-titanium-based disordered rock-salt cathode materials.
基于锰的阳离子无序岩盐（DRX）阴极材料因其成本效益高和比容量高而展现出广阔的应用前景。然而，这些材料常用的合成方法依赖于固态反应法和机械化学法，这主要归因于低价态锰的影响。目前，用于制备基于锰的DRX阴极材料的溶胶 - 凝胶方法仅限于涉及锰的体系。此外，关于基于锰的DRX的改性研究较少。为了解决这一问题，以蔗糖为碳源，通过溶胶 - 凝胶法一步烧结工艺合成了亚微米级碳包覆的LiMnTiO/C材料，与在相同温度下通过固态反应制备的材料相比，其粒径更小。当用作锂电池的阴极材料时，用10 wt%蔗糖制备的样品表现出优异的循环稳定性，初始放电比容量为119.6 mA h g（电流密度为20 mA g）。经过20次充放电循环后，可逆比容量达到91.0 mA h g，容量保持率为76.1%。该方法为锰钛基无序岩盐阴极材料的制备和改性提供了独特的见解和策略。
