Microwave Plasma Chemical Vapor Deposition of SbxOy/C negative electrodes and their compatibility with lithium and sodium Hückel salts—based, tailored electrolytes

Mn-Substituted Tunnel-Type Polyantimonic Acid Confined in a Multidimensional Integrated Architecture Enabling Superfast-Charging Lithium-Ion Battery Anodes

Given the inherent features of open tunnel-like pyrochlore crystal frameworks and pentavalent antimony species, polyantimonic acid (PAA) is an appealing conversion/alloying-type anode material with fast solid-phase ionic diffusion and multielectron reactions for lithium-ion batteries. Yet, enhancing the electronic conductivity and structural stability are two key issues in exploiting high-rate and long-life PAA-based electrodes. Herein, these challenges are addressed by engineering a novel multidimensional integrated architecture, which consists of 0D Mn-substituted PAA nanocrystals embedded in 1D tubular graphene scrolls that are co-assembled with 2D N-doped graphene sheets. The integrated advantages of each subunit synergistically establish a robust and conductive 3D electrode framework with omnidirectional electron/ion transport network. Computational simulations combined with experiments reveal that the partial-substitution of H3O+ by Mn2+ into the tunnel sites of PAA can regulate its electronic structure to narrow the bandgap with increased intrinsic electronic conductivity and reduce the Li+ diffusion barrier. All above merits enable improved reaction kinetics, adaptive volume expansion, and relieved dissolution of active Mn2+/Sb5+ species in the electrode materials, thus exhibiting ultrahigh rate capacity (238 mAh g-1 at 30.0 A g-1), superfast-charging capability (fully charged with 56% initial capacity for ≈17 s at 80.0 A g-1) and durable cycling performance (over 1000 cycles).

Double conductivity-improved porous Sn/Sn4P3@carbon nanocomposite as high performance anode in Lithium-ion batteries

Carbon encapsulated porous Sn/Sn₄P₃ (Sn/Sn₄P₃@C) composite is conveniently prepared by one-step electrochemical dealloying of Sn₈₀P₂₀ alloy in mild conditions followed by growing one carbon layer. Controllable dealloying of the Sn₈₀P₂₀ alloy results in the formation of bicontinuous spongy Sn₄P₃ nanostructure with a part of residued metallic Sn atoms embedded in the porous skeleton. A uniform carbon layer is deposited on the nanoporous Sn/Sn₄P₃ to prevent the nanostructure's pulverizing and agglomerating during lithium ion insertion/extraction. Upon double conductivity modification from metallic Sn matrix and carbon layer, the as-made composite displays superior lithium-storage performances with much higher specific capacity as well as better cycling stability compared with pure porous Sn₄P₃. It offers a specific capacity of 837 mA h g^-1 after 100 cycles at a rate of 100 mA g^-1. Even after 700 cycles at the higher rate of 1000 mA g^-1, the specific capacity still maintains as high as 589 mA h g^-1. The Sn/Sn₄P₃@C material possesses promising application potential as an alternative anode in the lithium storage fields.

Alloy-Based Anode Materials toward Advanced Sodium-Ion Batteries

Sodium-ion batteries (SIBs) are considered as promising alternatives to lithium-ion batteries owing to the abundant sodium resources. However, the limited energy density, moderate cycling life, and immature manufacture technology of SIBs are the major challenges hindering their practical application. Recently, numerous efforts are devoted to developing novel electrode materials with high specific capacities and long durability. In comparison with carbonaceous materials (e.g., hard carbon), partial Group IVA and VA elements, such as Sn, Sb, and P, possess high theoretical specific capacities for sodium storage based on the alloying reaction mechanism, demonstrating great potential for high-energy SIBs. In this review, the recent research progress of alloy-type anodes and their compounds for sodium storage is summarized. Specific efforts to enhance the electrochemical performance of the alloy-based anode materials are discussed, and the challenges and perspectives regarding these anode materials are proposed.