Rational designing of MoSe2 nanosheets in carbon framework for high-performance potassium-ion batteries

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Switzerland : 1996), 2022-11, Vol.448, p.137658, Article 137658
• Main Authors: Tao, Jianming, Yan, Zerui, Wang, Daoyi, Zhong, Wenhao, Yang, Yanmin, Li, Jiaxin, Lin, Yingbin, Huang, Zhigao
• Format: Article
• Language: English
• Subjects: MoSe2; Potassium-ion batteries; Spatial distribution; Stress; Ultrasonic spray
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2022.137658

It is highly desirable to clarify the relationship between the spatial distribution of active material and the electrochemical performances, providing novel insights on exploration of high-performance anodes modified with carbon. In our work, we found that homogeneous MoSe2-distribution in carbon framework expectantly helps to form uniform stress gradient, relieve local stress and promote SEI-film stability upon cycling. [Display omitted] •MoSe2/C microspheres are prepared via ultrasonic spray under vacuum.•Space distribution of MoSe2 in composites depends on solutions concentration.•Uniform distribution of MoSe2 in composites exhibit better cycling stability.•Uniform distribution of MoSe2 benefit to stable SEI-film growth and stress relief. Carbon-composting is considered as most promising strategy for high-performance anodes of alkali metal ion batteries in viewpoint of improving electric-conductivity and alleviating volume expansion. Spatial distribution of active material in carbon-composting anodes should play a vital role in electron/ion migration, SEI-film growth and stress relief upon ion insertion/extraction. Herein, spatial distribution of MoSe2 in MoSe2/C composites is regulated by controlling the concentration of precursor solutions. Interestingly, uniform distribution of MoSe2 in carbon framework seems to exhibit better cycling-stability than either core-rich MoSe2 or shell-rich MoSe2 composites. In contrast to the suppressed K-ion kinetics in core-rich MoSe2 and the surface cracking in surface-rich MoSe2, homogeneous MoSe2-distribution in MoSe2/C is beneficial for local stress relief, enhanced K+-ion migration and stable SEI-film evolution upon cycling. We believe that the strategy based on spatial distribution of active material in composite would provide novel insights on exploration of high-performance anodes modified with carbon.