Applications of Tin Sulfide‐Based Materials in Lithium‐Ion Batteries and Sodium‐Ion Batteries

Sodium ion batteries and capacitors have demonstrated their potential applications for next-generation low-cost energy storage devices. These devices's rate ability is determined by the fast sodium ion storage behavior in electrode materials. Herein, a defective TiO2@reduced graphene oxide (M-TiO2@rGO) self-supporting foam electrode is constructed via a facile MXene decomposition and graphene oxide self-assembling process. The employment of the MXene parent phase exhibits distinctive advantages, enabling defect engineering, nanoengineering, and fluorine-doped metal oxides. As a result, the M-TiO2@rGO electrode shows a pseudocapacitance-dominated hybrid sodium storage mechanism. The pseudocapacitance-dominated process leads to high capacity, remarkable rate ability, and superior cycling performance. Significantly, an M-TiO2@rGO//Na3V2(PO4)3 sodium full cell and an M-TiO2@rGO//HPAC sodium ion capacitor are fabricated to demonstrate the promising application of M-TiO2@rGO. The sodium ion battery presents a capacity of 177.1 mAh g−1 at 500 mA g−1 and capacity retention of 74% after 200 cycles. The sodium ion capacitor delivers a maximum energy density of 101.2 Wh kg−1 and a maximum power density of 10,103.7 W kg−1. At 1.0 A g−1, it displays an energy retention of 84.7% after 10,000 cycles.

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MXene-Derived Defect-Rich TiO 2 @rGO as High-Rate Anodes for Full Na Ion Batteries and Capacitors

Recent Tactics and Advances in the Application of Metal Sulfides as High‐Performance Anode Materials for Rechargeable Sodium‐Ion Batteries

Advanced electrode materials embrace the key to the fundamental progress in rechargeable ion battery systems, which are essential to meet the finite nature of fossil fuels and the growing energy demands for clean and renewable energy. Metal phosphides in particular offer opportunities in rechargeable ion batteries owing to the extraordinarily high theoretical capacity and suitable redox potential. Notwithstanding these advantages, metal phosphides suffer from drastic volume variation during the electrochemical cycling process, resulting in relatively low capacity retention. Constructing metal phosphide–carbon heterostructures is an engrossing approach, which is because nanocarbon possesses bifunctional features that afford an electronic pathway and alleviate large volume expansion. Thus, the hybridization strategies of metal phosphides with different carbonaceous species are specifically highlighted in this review, followed by the illustration of how a robust understanding of these carbon matrixes within composites provides fundamental insights into the electronic conductivity, cycling durability, and rate capacity in metal phosphide electrodes. Meanwhile, the systematic discussion of the Li+/Na+/K+ ion storage mechanism in metal phosphides has also been expressly represented. Based on the insights, we outline the critical issues and challenges of metal phosphide/carbon heterostructures that need to be addressed to broaden their contribution in rechargeable ion batteries.

Progress and perspective of metal phosphide/carbon heterostructure anodes for rechargeable ion batteries

Potassium-ion hybrid capacitors (KIHCs) have attracted increasing research interest because of the virtues of potassium-ion batteries and supercapacitors. The development of KIHCs is subject to the investigation of applicable K+ storage materials which are able to accommodate the relatively large size and high activity of potassium. Here, we report a cocoon silk chemistry strategy to synthesize a hierarchically porous nitrogen-doped carbon (SHPNC). The as-prepared SHPNC with high surface area and rich N-doping not only offers highly efficient channels for the fast transport of electrons and K ions during cycling, but also provides sufficient void space to relieve volume expansion of electrode and improves its stability. Therefore, KIHCs with SHPNC anode and activated carbon cathode afford high energy of 135 Wh kg−1 (calculated based on the total mass of anode and cathode), long lifespan, and ultrafast charge/slow discharge performance. This study defines that the KIHCs show great application prospect in the field of high-performance energy storage devices.
Highlights:
1 The hierarchically porous nitrogen-doped carbon (SHPNC) was fabricated by biorenewable carbon sources.2 The SHPNC electrode exhibited a high specific capacity, excellent cyclic stability, and superior rate capability.3 The asymmetric potassium-ion hybrid capacitors delivered a maximum energy density of 135 Wh kg−1, long lifespan with excellent capacity retention, and outstanding ultrafast charge/slow discharge performance.

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Cocoon Silk-Derived, Hierarchically Porous Carbon as Anode for Highly Robust Potassium-Ion Hybrid Capacitors

Constructing unique and highly stable structures with plenty of electroactive sites in sodium storage materials is a key factor for achieving improved electrochemical properties through favorable sodium ion diffusion kinetics. An SnS2@carbon hollow nanospheres (SnS2@C) has been designed and fabricated via a facile solvothermal route, followed by an annealing treatment. The SnS2@C hybrid possesses an ideal hollow structure, rich active sites, a large electrode/electrolyte interface, a shortened ion transport pathway, and, importantly, a buffer space for volume change, generated from the repeated insertion/extraction of sodium ions. These merits lead to the significant reinforcement of structural integrity during electrochemical reactions and the improvement in sodium storage properties, with a high specific reversible capacity of 626.8 mAh g−1 after 200 cycles at a current density of 0.2 A g−1 and superior high-rate performance (304.4 mAh g−1 at 5 A g−1).

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SnS2@C Hollow Nanospheres with Robust Structural Stability as High-Performance Anodes for Sodium Ion Batteries

Hollow CoS2@C nanocubes for high-performance sodium storage

The constructing of functional materials with well-defined nanostructure, showing efficient charge separation and transportation properties, has been intensively and in depth investigated to fabricate catalysts for H2 generation from solar-driven water reduction. Here we demonstrate that loading W2C@C structure in which each W2C nanoparticle (NP) is wrapped by carbon shell on surface of hollow TiO2 microspheres (HTMs) can enhance the separation of photogenerated electron-hole pairs by building an internal electric field in W2C@C/HTMs composite structure and act as the reaction active sites for water reduction. As expected, the optimized W2C@C/HTMs construction exhibits the highest photocatalytic H2 generation rate of 6.91 mmol h−1 g−1 under simulated solar light illumination, over 20 times larger than that of bare HTMs. The underlying mechanism has been investigated from the perspective of photochemistry and photophysics based on a series of characterization techniques, which suggests that W2C@C can effectively steer the charge kinetics, maximizing the charge carriers’ separation.

Steering charge kinetics in W2C@C/TiO2 heterojunction architecture: Efficient solar-light-driven hydrogen generation

Constructing hollow architectures based on metal sulfides is of great interest for high-performance electrode materials for sodium-ion batteries because of their intriguing properties and various applications. However, the relatively low volumetric density and high fragile structure are the obstacles blocking the development of hollow-structured electrode materials. In this work, ball-in-ball structured (Ni0.33Co0.67)9S8@C nanospheres have been synthesized by using NiCo-glycerate as the precursor via solvothermal reaction, which was followed by a carbon coating treatment. In this structural design, hollow cavities are generated between the inner and outer balls to effectively accommodate the volume changes of the metal sulfides in the processes of charging/discharging, whereas the uniform carbon coating can increase the electrical conductivity and maintain the structural stability during repeated cycling. The Rietveld refinement, in situ X-ray diffraction, and ex situ X-ray photoelectron spectroscopy analyses provide evidence for an enlarged lattice parameter, weaker Co-S and Ni-S bondings, and a synergistic effect in (Ni0.33Co0.67)9S8@C toward boosting the conversion reaction and reversible formation of sulfur in the fully charged state, with sulfur trapped within the composite to additionally account for the superior cycling stability of this material. Capacitive behavior has been verified to dominate the electrochemical reaction, enabling fast charge-transport kinetics. Impressively, the double structural protection combined with the free hollow space and complete carbon layer endows the (Ni0.33Co0.67)9S8@C nanospheres with good electrochemical performance, featuring high cyclability and good rate capability.

Shuaihui Li

Papers

SnS2@C Hollow Nanospheres with Robust Structural Stability as High-Performance Anodes for Sodium Ion Batteries

Hollow CoS2@C nanocubes for high-performance sodium storage

Steering charge kinetics in W2C@C/TiO2 heterojunction architecture: Efficient solar-light-driven hydrogen generation

Engineering Unique Ball-In-Ball Structured (Ni0.33Co0.67)9S8@C Nanospheres for Advanced Sodium Storage.

Ball-in-ball structured SnO2@FeOOH@C nanospheres toward advanced anode material for sodium ion batteries