Integrated energy conversion and storage devices: Interfacing
(A) Scheme of the integrated system consisting of a-Si/H solar cells, NiCo 2 O 4 //AC BSHs and light emitting diodes (LEDs) as the energy conversion, storage and utilization devices; (B) Ragone''s plot of BSH at different current densities; (C) J-V curve of single-junction a-Si/H solar cells; (D) Charge-discharge curve of the NiCo 2 O 4 //AC BSHs powered by the