Sheet-like NiCo-layered double hydroxide anchored on NiTi alloy wire for extraordinary shape memory and high-performance supercapacitors

For wearable electronics, flexible supercapacitors with shape memory function can better meet the needs of practical applications. Herein, the porous Ni and NiCo-layered double hydroxide (NiCo-LDH) nanosheets were electrodeposited on the shape memory alloy wire (SMAW) to obtain the wire-shaped NiCo-LDH@Ni@SMAW electrodes with excellent electrochemical performance and shape memory ability. The maximum specific capacity of the electrode reaches 515.0 C g –1 at 0.2 A g –1 . The shape memory supercapacitor (SMSC) assembled by the NiCo-LDH@Ni@SMAW positive electrode and the activated carbon fiber yarn negative electrode exhibits good flexibility and excellent shape memory performance, which can return to the original shape within a few seconds and has a high capacitance retention of 81.5% after 50 shape recovery cycles. In addition, the SMSC also shows high energy density (136.6 μWh cm –2 ), power density (36 mW cm –2 ) and cycling stability (92.5% capacitance retention after 10,000 cycles). Graphical Abstract