Unveiling Manganese Malate as an Electrode Material for Supercapacitors

Supercapacitors are attractive due to their rapid charge storage/release capabilities and long cycle-life. However, their energy density is lower than batteries. The research community is continuously developing new electrode materials with high energy and high power capabilities. In view of this, manganese malate is unveiled as an electrode material for supercapacitor applications. Manganese malate is electrodeposited on a stainless-steel foil (area: 2 cm²) by chronoamperometry at various cell voltages (2/3/4 V). While X-ray diffraction and infrared spectroscopic studies confirm the formation of manganese malate, electron microscopic studies reveal that the morphology of manganese malate deposit is nanoparticulate. Manganese malate electrodeposited at 2 V (MnM2) delivers a specific capacitance of 186 F g^-1 at 1 A g^-1, and stable cycle-life over 10000 cycles in 0.1 M Mg(ClO₄)₂. In addition, a symmetric supercapacitor fabricated using MnM2 delivers a specific energy of 6.25 Wh kg^-1 at a specific power of 250.2 W kg^-1.