Transparent supercapacitors with networked MXene on NiCo-layered double hydroxide

This study investigates the growth mechanisms of NiCo-layered double hydroxide (LDH) electrodeposition on indium tin oxide (ITO) substrates, aiming to optimize thickness control for transparent supercapacitor applications. Despite the promising energy storage capabilities of NiCo-LDH, long-term cycle stability and transparency degradation due to irreversible redox reactions limit its applicability. To address these challenges, we introduced networked MXene nanosheets into the NiCo-LDH matrix, significantly enhancing electrochemical properties and cycle resilience while maintaining excellent transparency. Under optimized conditions, NiCo-LDH and MXene composites achieved an impressive areal capacitance of 136.9F cm⁻² and retained 74.2 % capacitance even after 7000 charge–discharge cycles. Notably, the transparency of the composite remained strong at 80.1 %, outperforming NiCo-LDH without the networked MXene, which retained only 51.4 % transparency after the same cycles, thus indicating that the well-networked MXene nanosheets played a crucial role in improving electrical conductivity and charge-transfer efficiency across the electrode surface. The transparent symmetric supercapacitor developed, utilizing MXene-coated NiCo-LDH, demonstrated outstanding performance with an energy density of 2.23 µWh cm⁻² at a power density of 120.00 µW cm⁻². Moreover, it showcased an admirable capacitance retention of 85.9 % following 9000 charge–discharge cycles, underlining the robustness of the composites and efficiency for transparent supercapacitor applications. In conclusion, this research highlights the potential of NiCo-LDH/MXene composites for transparent supercapacitors. By carefully controlling thickness and optimizing MXene concentration, we effectively addressed durability and transparency challenges during extended charge–discharge cycles.