The review of sodium and potassium-ion battery advances in density functional theory: Progresses, challenges and prospects

Sodium-ion batteries (SIBs) and potassium-ion batteries (PIBs) have emerged as promising alternatives for large-scale energy storage due to their abundant raw materials, low cost, and high safety. Density functional theory (DFT) has become a crucial technique for screening electrode materials due to the high cost and time-consuming nature of experimental research. Therefore, we present a systematic discussion of DFT applications in SIBs and PIBs studies. This review first outlines DFT processes and related concepts, including theoretical development, computational content, relevant software, and boundary condition description. It then clarifies the working principles and key challenges of SIBs and PIBs. The third part focuses on three primary implements of DFT. First, structural stability is enhanced through energy reduction, as demonstrated by structural optimization, defect design, and composite phase analysis. Second, the relationship between electronic structure modifications and battery performance is elucidated by examining molecular orbitals, charge density, band structures, and density of states. Third, superior reaction kinetics are predicated upon the identification of optimal ion migration pathways and minimal energy barriers. Finally, to address the inherent limitations of DFT, particularly in computational efficiency, the restricted scale of atoms and electrons, and the accurate modelling of electrochemical conditions, it is recommended to integrate DFT with machine learning and other computational approaches. This combined approach leverages complementary strengths to enhance efficiency and expand simulation scale. This review serves as a valuable reference for research on superior performance SIBs and PIBs, promoting more efficient energy storage solutions.