Unveiling K-storage mechanisms in Te-based electrodes for potassium-ion batteries

Potassium-ion batteries (PIBs) are drawing significant attention in the energy storage community because of their merits, including high power density, low redox potential, wide operating temperature range, and cost-effectiveness. However, their large-scale application is still limited by challenges like modest capacity, short cycle life, and severe electrode volume variation. Among the various electrode options, tellurium (Te)-based materials have emerged as promising candidates owing to their superior electrical conductivity, high theoretical capacity, and unique structural characteristics. This review summarizes recent developments on elemental Te, metal tellurides, Te-containing compounds, and Te-doped frameworks for PIB electrodes. The discussion focuses on their electrochemical behavior, potassium (K) storage mechanisms, and structural changes during cycling. Furthermore, strategies such as morphology design, composite construction, and defect engineering are highlighted for enhancing stability, rate capability, and K⁺ transport kinetics. Finally, key challenges and future directions are presented to guide the design of next-generation Te-based PIB electrodes.