Advancing Post‐Secondary Batteries under Lean Electrolyte Conditions through Interfacial Modification Strategies

Abstract In response to the growing global demand for portable electronics and electric vehicles, there is an escalating interest in developing advanced battery technologies with superior energy density. Research efforts are focused on unveiling post‐lithium‐ion batteries (LIBs) that outperform the performance of current LIBs through the use of innovative active electrode materials. Yet, these technological advancements face significant hurdles, primarily due to intricate interfacial issues within battery components. In laboratory‐scale studies, these challenges often lead to the utilization of excess electrolytes, which complicates the precise evaluation of battery performance. This review emphasizes the significance of designing future batteries that operate effectively under lean electrolyte usage conditions. It discusses essential principles, obstacles, and diverse strategies for interfacial modification, including in situ growth, coating of supportive layers, and embedding of active substances in pre‐structured templates. Furthermore, it compiles and examines data on the lean electrolyte conditions achieved in various battery systems, contrasting their energy densities with those of commercially established batteries. Ultimately, the potential of future batteries to achieve or even exceed the energy densities of existing commercial batteries is assessed, thereby offering a strategic roadmap for the progression of next‐generation battery technologies.