MD Adil1 Prasit Dutta1 Sagar Mitra1

1, Indian Institute of Technology Bombay, India, Mumbai, , India

There is a pressing need of new and advanced and cost effective stationary energy storage systems in concomitance with the fast development of solar, wind and other types of renewable sources of energy. The capability of high-rate cycling and environmental benignity at less expensive defines the ingress of upcoming energy storage systems. Multivalent ion batteries are emerging as a promising alternative of Li ion technology due to their natural abundance, safety, low cost proposition and higher volumetric capacity. But these batteries are still challenged by sluggish cation diffusion in the electrode material and high polarisation of the respective cations (Mg2+ Zn2+ Al3+). Calcium ion on the contrary have low polarisation compare to Li-ion, thus enjoying the benefits of overcoming the kinetics issues in large. Here, we introduce a reversible electrochemistry of Ca-ion cell in conjunction with inexpensive aqueous electrolyte, 1 M aqueous Ca(ClO4)2. Prussian Blue analogue barium hexacyanoferrate (BaHCF) cathode half-cell provides a capacity of 70 mAh/g with around 93% reversibility and 97% discharge capacity retention after 200 cycle was observed. In full cell, carbon cloth, BaHCF and meso-carbon microbeads (MCMB) have been explored as the current collector, cathode and anode material, respectively. The full cell provides 40 mAh/g (based on the mass of cathode active material) capacity at 5C rate till 100 cycles. We believe, the investigation of this simple full cell at the early stage of Ca-ion battery that will pave a fast transition in the forthcoming energy storage systems.