Recent progress and perspectives on composite structural layered transition metal oxides for sodium-ion batteries

Abstract

Layered transition metal oxides (LTMOs) are regarded as a compelling candidate for the prospective commercialization of sodium-ion batteries (SIBs), attributed to their simplistic architectural design, elevated operating potential window, and the feasibility of synthesis and tailoring. Nevertheless, a prevalent issue with many of these materials is their susceptibility to degradation under ambient conditions and suboptimal electrochemical behaviors. In light of these considerations, the multiphasic and synergistic effects exhibited by composite structural LTMOs for SIBs have emerged as a potent strategy to mitigate the aforementioned challenges. Furthermore, at present, the mechanistic insights into the synergistic interactions among multiple phases remain fragmented. This review offers a comprehensive synopsis of the advancements in research pertaining to composite structural LTMOs in SIBs, encompassing layered heterogeneous phases, multiphase composites, core–shell structures, and concentration gradient structures. Notably, this extensive overview delves into the intricate structure–function–performance relationship of phase interfaces and offers insights into predictive methodologies, synthetic strategies, and comprehensive materials characterization techniques, in order to pave a new avenue for future research, endeavors focused on composite-structured LTMOs, and fostering the development of more robust and efficient sodium-ion battery materials.