A novel hybrid sodium ion capacitor based on Na [Ni0.60Mn0.35Co0.05] O2 battery type cathode and presodiated D-Ti3C2Tx pseudocapacitive anode

Abstract

The combination of the high-power density of supercapacitors and the high energy density of batteries makes hybrid sodium-ion capacitors (HSICs) a promising device. HSICs can provide better performance characteristics by harnessing both ion adsorption/desorption in the capacitor-type electrode and sodium-ion intercalation in the battery-type electrode. Here, the synthesis of MXene (Ti3C2Tx), a two-dimensional (2D) carbide and nitride is reported. Delaminated MXene (D-Ti3C2Tx) is a promising candidate for anode material in HSIC due to its large surface area (∼ 42 m2/g) and good electronic conductivity. Electrochemical study indicates that D-Ti3C2Tx anode exhibits a high discharge capacity of ∼213 mAh/g at a current rate of 20 mA/g. Further the presodiated D-Ti3C2Tx anode is paired with Na [Ni0.60Mn0.35Co0.05] O2 (P2-NMC) cathode to obtain the configuration of HSIC. The HSIC exhibits good specific capacitance of ∼187 F/g and specific discharge capacity of ∼110 mAh/g at a current density of 10 mA/g, according to the electrochemical analysis. A notable improvement in specific energy density (∼ 256 Wh/kg) and specific power density (∼579 W/kg) is also demonstrated by the HSIC. With P2-NMC being used as the cathode material rather than traditional activated carbon, there has been a rise in specific energy density. © 2024 Elsevier B.V.