Recovery of bi-metallic oxalates from low grade Mn ore for energy storage application

The depletion of primary resources has led to exploitation of secondaries which are a promising source for the future if explored wisely. The authors report a novel approach of leaching low grade manganese ore and evaluation of the energy storage properties of the precipitated oxalates. The reaction rates were around 3.57 and 2.05 approximately in presence of oxalic acid and 1.92 and 0.43 respectively in presence of acid mix. The energy storage capacity of the precipitated metal oxalates has been thoroughly investigated. Oxalate sample with Fe:Mn ratio of 0.67 showed the highest energy storage behaviour with 86.9 Fg−1 specific capacitance values with 94.3% retention after 1000 cycles. Energy density of 15.4 WhKg−1 and power density of 80 WKg−1 was obtained at 0.1 Ag−1 current density.