High-Performance Cathode Materials for Potassium-Ion Batteries: Structural Design and Electrochemical Properties

Due to the obvious advantage in potassium reserves, potassium-ion batteries (PIBs) are now receiving increasing research attention as an alternative energy storage system for lithium-ion batteries (LIBs). Unfortunately, the large size of K+ makes it a challenging task to identify suitable electrode materials, particularly cathode ones that determine the energy density of PIBs, capable of tolerating the serious structural deformation during the continuous intercalation/deintercalation of K+. It is therefore of paramount importance that proper design principles of cathode materials be followed to ensure stable electrochemical performance if a practical application of PIBs is expected. Herein, the current knowledge on the structural engineering of cathode materials acquired during the battle against its performance degradation is summarized. The K+ storage behavior of different types of cathodes is discussed in detail and the structure-performance relationship of materials sensitive to their different lattice frameworks is highlighted. The key issues facing the future development of different categories of cathode materials are also highlighted and perspectives for potential approaches and strategies to promote the further development of PIBs are provided.

Automated summary

Potassium-ion batteries (PIBs) are gaining research attention as an alternative energy storage system to lithium-ion batteries (LIBs) due to their advantage in potassium reserves. Finding suitable electrode materials, especially cathode materials that can withstand the serious structural deformation during continuous potassium intercalation/deintercalation, is crucial for stable electrochemical performance. The relationship between material lattice frameworks and performance is discussed, along with potential strategies for future development of PIBs.