SnO2 /Sn Nanoparticles Embedded in an Ordered, Porous Carbon Framework for High-Performance Lithium-Ion Battery Anodes

Fast Energy Storage of SnS2 Anode Nanoconfined in Hollow Porous Carbon Nanofibers for Lithium-Ion Batteries

The development of conversion-typed anodes with ultrafast charging and large energy storage is quite challenging due to the sluggish ions/electrons transfer kinetics in bulk materials and fracture of the active materials. Herein, the design of porous carbon nanofibers/SnS2 composite (SnS2 @N-HPCNFs) for high-rate energy storage, where the ultrathin SnS2 nanosheets are nanoconfined in N-doped carbon nanofibers with tunable void spaces, is reported. The highly interconnected carbon nanofibers in three-dimensional (3D) architecture provide a fast electron transfer pathway and alleviate the volume expansion of SnS2 , while their hierarchical porous structure facilitates rapid ion diffusion. Specifically, the anode delivers a remarkable specific capacity of 1935.50 mAh g-1 at 0.1 C and excellent rate capability up to 30 C with a specific capacity of 289.60 mAh g-1 . Meanwhile, at a high rate of 20 C, the electrode displays a high capacity retention of 84% after 3000 cycles and a long cycle life of 10 000 cycles. This work provides a deep insight into the construction of electrodes with high ionic/electronic conductivity for fast-charging energy storage devices.

SnS Nanosheets Confined Growth by S and N Codoped Graphene with Enhanced Pseudocapacitance for Sodium-Ion Capacitors

Layered tin monosulfide (SnS) is a promising anode material for sodium-ion batteries because of its high theoretical capacity of 1020 mA h g^-1. Its large interlayer spacing permits fast sodium-ion transport, making it a viable candidate for sodium-ion capacitors (SICs). In this work, we designed and synthesized oriented SnS nanosheets confined in graphene in the presence of poly(diallyl dimethyl ammonium chloride) by electrostatic self-assembly during hydrothermal growth. SnS nanosheets growing along (l00) and (0l0) directions are suppressed because of the confinement by graphene, which exhibit smaller thickness and particle size. These nanostructures expose abundant open edges because of the presence of Sn⁴⁺-O, which offers rich active sites and Na⁺ easy transport pathways. Vacancies formed at these edges along with S and N codopants in the graphitic structure synergistically promoted Na⁺ surface adsorption/desorption. Such nanocomposites with SnS nanosheets confined by N,S codoped graphene demonstrated significantly enhanced pseudocapacitance. The SICs delivered excellent energy densities of 113 and 54 W h kg^-1 at power densities of 101 and 11 100 W kg^-1, respectively, with 76% capacity retention after 2000 cycles at 1 A g^-1.

Metallic Sn-Based Anode Materials: Application in High-Performance Lithium-Ion and Sodium-Ion Batteries

With the fast-growing demand for green and safe energy sources, rechargeable ion batteries have gradually occupied the major current market of energy storage devices due to their advantages of high capacities, long cycling life, superior rate ability, and so on. Metallic Sn-based anodes are perceived as one of the most promising alternatives to the conventional graphite anode and have attracted great attention due to the high theoretical capacities of Sn in both lithium-ion batteries (LIBs) (994 mA h g-1) and sodium-ion batteries (847 mA h g-1). Though Sony has used Sn-Co-C nanocomposites as its commercial LIB anodes, to develop even better batteries using metallic Sn-based anodes there are still two main obstacles that must be overcome: poor cycling stability and low coulombic efficiency. In this review, the latest and most outstanding developments in metallic Sn-based anodes for LIBs and SIBs are summarized. And it covers the modification strategies including size control, alloying, and structure design to effectually improve the electrochemical properties. The superiorities and limitations are analyzed and discussed, aiming to provide an in-depth understanding of the theoretical works and practical developments of metallic Sn-based anode materials.