High Capacitive Antimonene/CNT/PANI Free‐Standing Electrodes for Flexible Supercapacitor Engaged with Self‐Healing Function

In virtue of the high electrochemical activity and inherent flexibility, polyaniline (PANI) is an ideal electrode material for flexible supercapacitors (SCs). However, in practical applications, the inevitable agglomeration of PANI leads to low capacitance, poor rate performance, and cycling stability. Here, antimonene (Sb) nanosheets with ultrathin thickness, excellent mechanical strength, and flexibility are introduced into the carbon nanotube (CNT) framework for PANI electrodeposition via simple vacuum filtration, which enables the continuous and uniform growth of PANI. The resultant free-standing Sb/CNT/PANI electrode can thus exhibit a high specific capacitance of 578.57 F g^-1 together with a high rate capability. Besides, thanks to the introduction of Sb nanosheets, the agglomeration of PANI during the electrodeposition is improved, which correspondingly alleviates the structural deterioration of PANI during repeated charge/discharge. Thus, the flexible SC assembled by Sb/CNT/PANI electrodes demonstrates both an impressive specific capacitance of 416 F g^-1 and outstanding cycling stability over 12 000 cycles. Moreover, this SC device can have a practical self-healing function by employing self-healable polyurethane. The facile strategy reported herein sheds light on the design of high-performance flexible SCs, catering to the needs of portable and wearable electronics.