Integration of conductive polymers with flexible substrate to construct an electronically conductive and mechanically flexible electrode is of great significance for a flexible energy storage device. This work reports a facile method to prepare coral-like poly(3,4-ethylenedioxythiophene) (PEDOT) nanotube arrays on textile carbon fibers (TCs) for high-rate supercapacitor application. The ZnO nanowires grown on TCs serve as a sacrificial template. Electrochemical polymerization of 3,4-ethylenedioxythiophene followed by template removal of ZnO nanowires yields a hybrid composed of PEDOT nanotubes vertically grown on TC (TC@PEDOT). The strong interfacial interactions between nanotubes and substrate afford the hybrid with superior mechanical flexibility and high conductivity (790 S m −1 ). More importantly, the tubular structure enables ∼88% PEDOT to be involved in the reversible redox reaction, delivering a specific capacitance 184 F g −1 in 1.0 M H 2 SO 4 electrolyte with 88% capacitance retention after 10 000 cycles. A solid-state TC@PEDOT-based supercapacitor with PVA-H 2 SO 4 as gel electrode exhibits a high-rate capability with a relaxation time constant (τ 0 = 0.96 s) very close to that in aqueous H 2 SO 4 electrolyte (τ 0 = 0.87 s). Moreover, it can withstand various bending and twisting tests without notable performance loss, giving the TC@PEDOT hybrid great promise as a high-rate electrode for flexible energy storage devices.

By using Ti3C2T x quantum dots as interlayer spacers, Ti3C2T x nanosheets/Ti3C2T x quantum dots/RGO (reduced graphene oxide) fiber (M6M3RG1) is prepared by a wet-spinning method; it shows good capacitance and excellent flexibility. The M6M3RG1 fiber electrode possesses a novel network structure and a maximum volumetric capacitance of 542 F cm–3, and its capacitance and flexibility are affected by the amount of Ti3C2T x quantum dots. Also, the Ti3C2T x /PEDOT:PSS [poly­(3,4-ethylenedioxythiophene):poly­(styrenesulfonate)] fiber (M7P3) is prepared by injecting a homogeneous suspension of Ti3C2T x nanosheets and PEDOT:PSS into a bath of 98 wt % H2SO4. The M6M3RG1 fiber is used as the positive electrode, and the M7P3 fiber is used as the negative electrode; a M6M3RG1//M7P3 asymmetric, flexible, solid-state supercapacitor is assembled in a PVA–H2SO4 gel electrolyte. The assembled device exhibits a volumetric capacitance of 53.1 F cm–3 and a good cycle stability of 96.6% after 5000 cycles. It also shows outstanding flexibility and mechanical properties; for example, the volumetric capacitance has no obvious change after the device is bent at 90° for 500 times. Moreover, its voltage window can be expanded to 1.5 V, and a maximum volumetric energy density of 16.6 mWh cm–3 can be achieved. This work will open up a new application area for new wearable energy storage devices based on the Ti3C2T x fibers.

Developing new optimized bifunctional photocatalyst is of great significant for achieving the high-performance photo-assisted Li-O 2 batteries. Herein, a novel bifunctional photo-assisted Li-O 2 system is constructed by using siloxene nanosheets with ultra-large size and few-layers due to its superior light harvesting, semiconductor characteristic, and low recombination rate. An ultra-low charge potential of 1.90 V and ultra-high discharge of 3.51 V have been obtained due to the introduction of this bifunctional photocatalyst into Li-O 2 batteries, and these results have realized the round-trip efficiency up to 185 %. In addition, this photo-assisted Li-O 2 batteries exhibits a high rate (129 % round-trip efficiency at 1 mAcm À2 ), a prolonged cycling life with 92 % efficiency retention after 100 cycles, and the highly reversible capacity of 1170 mAh g À1 at 0.75 mA cm À2 . This work will open the vigorous opportunity for high-efficiency utilization of solar energy into electric system.

Rechargeable magnesium batteries are a promising alternative to Li‐based energy storage because of their abundant and inexpensive components. The high sensitivity and reactivity of the organic Mg2+ electrolyte makes their development challenging. Herein, we develop a new hybrid electrolyte, based on three simple inorganic salts of MgCl2, AlCl3, and Mg(TFSI)2. The electrolyte exhibits unprecedented electrochemical performance for reversible deposition and stripping of Mg, with Coulombic efficiency up to 97 %, overpotential down to 0.10 V, good stability especially for aluminum and stainless‐steel current collectors. It maintained its activity even after introducing 2000 ppm water and it could be prepared from impure chemicals. A full cell with the hybrid electrolyte and Mg foil as anode, Mo6S8 as cathode gave a specific capacity of 98 mAh g−1 and maintained 94 % capacity after 100 cycles at a rate of 0.20 C, indicating the good compatibility of the hybrid electrolyte.