New Emerging Fast Charging Microscale Electrode Materials.

Fast charging lithium (Li)-ion batteries are intensively pursued for next-generation energy storage devices, whose electrochemical performance is largely determined by their constituent electrode materials. While nanosizing of electrode materials enhances high-rate capability in academic research, it presents practical limitations like volumetric packing density and high synthetic cost. As an alternative to nanosizing, microscale electrode materials cannot only effectively overcome the limitations of the nanosizing strategy but also satisfy the requirement of fast-charging batteries. Therefore, this review summarizes the new emerging microscale electrode materials for fast charging from the commercialization perspective. First, the fundamental theory of electronic/ionic motion in both individual active particles and the whole electrode is proposed. Then, based on these theories, the corresponding optimization strategies are summarized toward fast-charging microscale electrode materials. In addition, advanced functional design to tackle the mechanical degradation problems related to next generation high capacity alloy- and conversion-type electrode materials (Li, S, Si et al.) for achieving fast charging and stable cycling batteries. Finally, general conclusions and the future perspective on the potential research directions of microscale electrode materials are proposed. It is anticipated that this review will provide the basic guidelines for both fundamental research and practical applications of fast-charging batteries.