Element substitution of a spinel LiMn2O4 cathode

Spinel LiMn2O4 is a promising cathode material for lithium-ion batteries ascribed to its steady bulk structure and abundant manganese sources. Nevertheless, severe capacity decay due to the Jahn-Teller effect and spontaneous disproportionation reaction seriously hampers its extensive application, especially at high-temperature or high-potential operation circumstances. Attributed to the strengthening of the crystallographic structure and the inhibition of Mn3+ side reactions, element substitution has become one of the most momentous tactics in the modification of LiMn2O4. Here, we comprehensively review the developments on restraining capacity fading and enhancing the performances of LiMn2O4 through element substitution. Primarily, the capacity fading mechanism of LiMn2O4 has been thoroughly recapitulated. Subsequently, our summary is proposed based on two categories, which are phase evolution and solid solution strengthening invoked by element substitution, and the latter can be subdivided into structure strengthening and Li+ diffusion kinetics boosting. More importantly, we put forward a methodological approach for future element substitution research studies. This report will shed light on the future direction of LiMn2O4 cathode material optimization.

Automated summary

This paper comprehensively reviews the developments in restraining capacity fading and enhancing the performance of LiMn2O4 through element substitution. It thoroughly summarizes the capacity fading mechanism and categorizes the effects of element substitution into phase evolution and solid solution strengthening, which includes structure strengthening and Li+ diffusion kinetics boosting. Furthermore, a methodological approach for future element substitution research studies is proposed to guide the optimization of LiMn2O4 cathode material in the future.