The exploration of high-energy anodes with good mechanical properties is highly attractive for flexible asymmetric supercapacitors (ASCs) but challenging. Owing to the excellent conductivity and superior mechanical flexibility, carbon fiber textile (CFT) holds great promise as a substrate/ current-collector for fabricating flexible electrodes. Yet, it is rarely used as a flexible active electrode in terms of its low electrochemical reactivity and small accessible area. In this work, an effective surface and structural modulation strategy is developed to directly tune CFT into a highly active anode for flexible ASCs by creating hierarchical pores and numerous pseudocapacitive oxygenic groups. Arising from large surface and increased active sites, the as-prepared activated porous CFT (APCFT) electrode not only achieves a large capacitance (1.2 F cm −2 at 4 mA cm −2 ) and fast kinetics but also shows satisfying cycling durability (no capacitance decay after 25 000 cycles). More importantly, an advanced flexible ASC device with an impressive energy density of 4.70 mWh cm −3 is successfully assembled by employing this APCFT as an anode, outperforming most recently reported ASC devices. This dual modification strategy may throw light on the rational design of new generation advanced carbon electrodes for high-performance flexible supercapacitors.

A hybrid aqueous Na–Zn ion battery derived from the Na3V2(PO4)3 cathode is one of the most promising systems among aqueous batteries because it exhibits higher energy density than a pure Zn ion battery due to different ion intercalation mechanisms related to various electrolytes. However, it is more difficult to improve the electrochemical performance of the hybrid aqueous Na–Zn ion battery versus Zn ion battery. In addition, searching for suitable protective interphase film-forming electrolyte additives in order to increase cycling stability and developing a new electrolyte recipe to improve the low temperature performance are significant and still big challenges for the hybrid aqueous Na–Zn battery. Herein, the introduction of protective interphase film-forming additives (VC), an economical 10 M NaClO4–0.17 M Zn­(CH3COO)2-2 wt % VC electrolyte, was proposed. Based on such an electrolyte, the carbon-coated single crystalline Na3V2(PO4)3 nanofiber//Zn aqueous Na–Zn hybrid battery involving high energy, long cycle, and outstanding low temperature performance was successfully obtained. For example, it delivered a remarkable output voltage of 1.48 V and excellent cycle stability (retained 84% after 1000 cycles). The capacities were 94.4 mA h/g at 0.2 A/g at −10 °C and 90.0 mA h/g at 0.2 A/g at −20 °C, respectively.

State-of-the-art energy storage devices are highly attractive for the ever-worsening energy depletion and environmental deterioration. Among various candidates, supercapacitors (SCs) have been considered among the most promising energy storage devices. As key factors for the development of SCs, the electrode materials have been widely exploited, and great achievements have been made. Among these materials, carbonfiber materials, such as carbon nanofibers (CNFs), carbon cloths (CCs), and carbon fiber papers (CFPs), are considered as promising candidates for electrodes and supports/current collectors for other electrode materials, owing to their special physical/chemical properties and structures. This Minireview aims to provide an overview of recent advances and technologies to improve the electrochemical performance of these carbon-fiber materials and their composite electrodes. We also briefly outline the current challenges and perspectives for the development of these carbon-fiber materials and carbon-fiberbased composite electrode materials.[a] Dr.