Heterostructured Ti₃C₂T_x loaded NiCoCu-based layered double hydroxide as a high-performance cathode for hybrid supercapacitors

Layered double hydroxides (LDHs) are regarded as a promising electrode material for supercapacitors. Nevertheless, their large-scale application is impeded by several drawbacks, such as low electronic conductivity, limited electroactive sites, and poor cycling stability. Two-dimensional titanium-based carbide (Ti₃C₂T_x) loading NiCoCu-based layered double hydroxide heterostructures (Ti₃C₂T_x@NiCoCu-LDH), which feature a layered and cross-linked network, were prepared to improve the electrochemical performance of NiCoCu-LDH. The layered network structure of Ti₃C₂T_x@NiCoCu-LDH enhances active site exposure and accommodates volume changes during cycling. Both the specific capacitance and structural stability of the electrode are improved. Additionally, Ti₃C₂T_x boosts the electronic conductivity of LDHs and accelerates the kinetics of electrochemical reactions. Ti₃C₂T_x@NiCoCu-LDH exhibits a high specific capacity of 1891.4 F·g⁻¹ (262.2 mAh·g⁻¹) at 1 A·g⁻¹ and exceptional cycling stability. When assembled into Ti₃C₂T_x@NiCoCu-LDH//activated carbon (AC) hybrid supercapacitor, it demonstrates a high energy density of 35.5 Wh·kg⁻¹ at 826.8 W·kg⁻¹. In addition, the supercapacitor maintains 81.6 % of initial capacitance after 20,000 cycles. This work has proposed a promissing MXene-based composite cathode for high-performance hybrid supercapacitors.