Fiber‐in‐Tube Design of Co₉S₈‐Carbon/Co₉S₈: Enabling Efficient Sodium Storage

Abstract

The sodium‐ion battery is a promising battery technology owing to its low price and high abundance of sodium. However, the sluggish kinetics of sodium ion makes it hard to achieve high‐rate performance, therefore impairing the power density. In this work, a fiber‐in‐tube Co9S8‐carbon(C)/Co9S8 is designed with fast sodiation kinetics. The experimental and simulation analysis show that the dominating capacitance mechanism for the high Na‐ion storage performance is due to abundant grain boundaries, three exposed layer interfaces, and carbon wiring in the design. As a result, the fiber‐in‐tube hybrid anode shows a high specific capacity of 616 mAh g−1 after 150 cycles at 0.5 A g−1. At 1 A g−1, a capacity of ca. 451 mAh g−1 can be achieved after 500 cycles. More importantly, a high energy density of 779 Wh kg−1 and power density of 7793 W kg−1 can be obtained simultaneously.

Electrospinning‐Based Strategies for Battery Materials

“…[ 17 ] Besides the original polymeric materials, electrospun materials now also include metals, ceramics, semiconductors and proteins, and combinations thereof. [ 13a ] Due to the large specific surface area, high porosity, and unique nanostructural and composite characteristics, [ 18 ] electrospun nanofibers encompass great application potential in energy storage, [ 19 ] drug release, [ 20 ] biosensing, [ 21 ] and filtration. [ 22 ] Nowadays, the electrospinning technology is not only limited to research in the laboratory but has also been applied to realistic industrial productions, demonstrating its general scalability.…”

Oxygen Vacancy‐Engineered Ti−Mo−Ni Ternary Oxide Nanotubes as Binder‐Free Supercapacitor Electrodes with Exceptional Potential Window

“…Energy storage is an incidental world problem. In this regard, developing energy storage devices (such as batteries, [1][2][3][4][5][6] fuel cells, [7] and supercapacitors [8] ) are necessary to ensure the efficient use of the generated energy. To this end, supercapacitors are advanced electrochemical devices that bridge the gap between batteries and conventional capacitors.…”

Redox Tuning in Crystalline and Electronic Structure of Bimetal–Organic Frameworks Derived Cobalt/Nickel Boride/Sulfide for Boosted Faradaic Capacitance

“…The peaks for Co and Ni are positively shifted, which indicates that the Co and Ni ions lose electrons and become oxidized (Figure S8b,c, Supporting Information). Besides, sulfurization is considered a violent reaction process for the metal ions and S 2− to form metal‐S bonds, which would stabilize of Co and Ni species and strengthen their antioxidizing ability . Although the reduction is carried out subsequently using sodium borohydride, the collapsed structure of Co‐Ni‐S could not be reversed into well‐developed sheet structure (Figure ).…”