Self-Standing Polypyrrole/Black Phosphorus Laminated Film: Promising Electrode for Flexible Supercapacitor with Enhanced Capacitance and Cycling Stability

Abstract

With the rapid development of portable electronics, solid-state flexible supercapacitors (SCs) are considered as one of the promising energy devices in powering electronics because of their intrinsic advantages. Polypyrrole (PPy) is an ideal electrode material in constructing flexible SCs owing to its high electrochemical activity and inherent flexibility, although its relatively low capacitance and poor cycling stability are still worthy of improvement. Herein, through the innovative introduction of black phosphorus (BP) nanosheets, we developed a laminated PPy/BP self-standing film with enhanced capacitance and cycling stability via a facile one-step electrochemical deposition method. The film exhibits a high capacitance of 497.5 F g (551.7 F cm) and outstanding cycling stability of 10 000 charging/discharging cycles, thanks to BP nanosheets inducing laminated assembly which hinder dense and disordered stacking of PPy during electrodeposition, consequently providing a precise pathway for ion diffusion and electron transport together with alleviation of the structural deterioration during charge/discharge. The flexible SC fabricated by laminated films delivers a high capacitance of 452.8 F g (7.7 F cm) besides its remarkable mechanical flexibility and cycling stability. Our facile strategy paves the way to improve the electrochemical performance of PPy-based SC that could serve as promising flexible energy device for portable electronics.

Honeycomb‐Lantern‐Inspired 3D Stretchable Supercapacitors with Enhanced Specific Areal Capacitance

“…However, the reported doped PPy composites usually present a dense structure, mainly including close‐packed structures and laminated structures. [9d,10] The mechanical stress developed in these dense‐packing PPy composites due to ion exchange in charging/discharging process would aggravate the cracking of PPy electrodes, leading to degradation of electrochemical and mechanical performance under extended periods of physical stress . Moreover, the dense structure greatly impedes electrolyte penetration and ion transport, which deteriorates the electrochemical performance at high charging/discharging rates .…”

Recent Progress of Two-Dimensional Thermoelectric Materials

“…As a novel elementary 2D material, the few-layer BP has gained tremendous attention in theoretical and experimental investigations [114][115][116][117][118][119]. Due to its unique crystal structure and in-plane anisotropic properties, BP has been widely studied in various fields including in the development of photodetectors [116,120,121], cancer therapies [115,122,123], supercapacitors [124], field-effect transistors (FETs) [125,126], batteries [127,128], and thermoelectric devices [39,98,[129][130][131][132][133].…”

“…Due to its unique electronic and optical properties, 2D BP has been widely studied in many research fields [114,120,[122][123][124][167][168][169][170][171][172][173][174]. Furthermore, it has been reported that it exhibits an ultrahigh Seebeck coefficient in the order of 10 mV K −1 , which makes it a promising thermoelectric materials.…”

Emerging Applications of Elemental 2D Materials

“…Moreover, the supercapacitor had a high capacitance retention (≈71.8%) after 30 000 cycles. Hybrids of black phosphorus with several other materials such as red phosphorus, graphene, polypyrrole have also been reported, exhibiting a wide range of specific and volumetric capacitances. Among other 2D materials, antimonene was recently employed in supercapacitors—screen printed EDLCs with carbon electrodes were fabricated with the addition of antimonene flakes, resulting in a very high specific capacitance (1578 F g −1 ) at a high current charging density (14 A g −1 ) …”