Emerging multimetal LMFP-based cathodes for lithium-ion batteries: A review

Abstract

The increasing demand for smart portable electronics and electric vehicles is driving advancements in high-energy-density lithium-ion batteries (LIBs). Among various cathode materials, lithium manganese iron phosphate (LiMnyFe1-yPO4 - LMFP) stands out due to its cost-effectiveness, excellent safety profile, long cycle life, high operating voltage, robust thermal stability, and competitive energy density. However, despite notable progress, LMFP still encounters key challenges such as limited electronic conductivity, sluggish Li-ion diffusion, manganese dissolution affecting cycling stability, and low tap density. To address these issues, significant efforts have been devoted to developing multimetal LMFP and other multimetal olivine-based cathodes with enhanced electrochemical properties. Nevertheless, a comprehensive review of these recent advancements remains lacking. This article aims to bridge this gap by examining emerging strategies and recent developments in multimetal LMFP cathodes for LIBs. It systematically compares various optimization approaches, including (i) doping with single or multiple elements at Li-, M-, or Li&M-sites, (ii) integrating additional primary constituents or structural components, and (iii) increasing the configurational entropy of electrode materials. The advantages and limitations of these strategies are critically assessed. Furthermore, key synthesis methodologies and processing techniques used to enhance LMFP cathode performance are discussed. Finally, the review provides insights into the benefits and challenges associated with these materials, highlighting future perspectives and potential research directions.