Boosting calcium-ion battery performance

Calcium batteries are considered an attractive alternative for next-generation energy storage because of the abundance of naturally available calcium and their high theoretical energy density. However, developing high-voltage positive electrodes for Ca-ion batteries remains challenging because Ca²⁺ ions diffuse poorly in conventional battery frameworks.

Alexandru Vlad (WEL Research Institute – UCLouvain) and collaborators developed amorphous conjugated carboxyphenolate framework, of the Ca₂-M-THBPD type, that improve calcium-ion mobility through flexible, disordered structures. The Ca₂-Ca-THBPD electrode operates at voltages above 3.5 V, delivers 120 mAh g⁻¹ capacity, and retains 75% capacity after 200 cycles. This work demonstrates that amorphous conjugated carboxyphenolate frameworks are promising active materials for durable, high-performance high-voltage calcium-ion batteries.

Reference: Bakuru et al, Carboxyphenolate coordination frameworks for high-voltage calcium storage, Adv Sci (2026) e75481