Hydrothermally synthesised CaMnO 3 with neutral Ca(NO 3 ) 2 electrolyte exhibited 258 F g −1 at 0.5 A g −1 within a potential of 1.9 V and showed 72.6% capacitance retention after 1500 cycles. The symmetric device delivered 76.1 F g −1 and powered a yellow LED.
Sukumaran et al. (2026) studied this question.