Molecular Engineering of Monodisperse SnO₂ Nanocrystals Anchored on Doped Graphene with High‐Performance Lithium/Sodium‐Storage Properties in Half/Full Cells

Abstract

The fabrication of ultrasmall and high‐content SnO2 nanocrystals anchored on doped graphene can endow SnO2 with superior electrochemical properties. Herein, an effective strategy, involving molecular engineering of a layer‐by‐layer assembly technique, is proposed to homogeneously anchor SnO2 nanocrystals on nitrogen/sulfur codoped graphene (NSGS), which serves as an advanced anode material in lithium/sodium‐ion batteries (LIBs/SIBs). Benefiting from novel design and specific structure, the optimized NSGS for LIBs displays high initial capacity (2123.9 mAh g−1 at 0.1 A g−1), long‐term cycling performance (only 0.8% loss after 500 cycles), and good rate capability (477.4 mAh g−1 at 5 A g−1). In addition, the optimized NSGS for SIBs also delivers high initial capacity (791.7 mAh g−1 at 0.1 A g−1) and high reversible capacity (180.2 mAh g−1 after 500 cycles at 0.5 A g−1). Meanwhile, based on the detailed analysis of phase transition and electrochemical reaction kinetics, the reaction mechanisms of NSGS in LIBs and SIBs as well as the distinction in LIBs/SIBs are clearly articulated. Notably, to further explore the practical application, Li/Na+ full cells are also assembled by coupling the optimized NSGS anode with LiCoO2 and Na3V2(PO4)3/C cathodes, respectively.

Tin Oxide Based Nanomaterials and Their Application as Anodes in Lithium‐Ion Batteries and Beyond

“…NIBs with SnO 2 ‐based anodes have gained considerable attention in recent years, with the first published examples of full cells. Knowledge transfer from the design of LIBs resulted in the fabrication of full cells with reversible capacities of up to about 108 mAh g −1 after 100 cycles at 0.1 C . It can be expected that research into SnO 2 ‐based anodes for NIBs will intensify due to the general attractiveness of NIBs, such as low cost, high abundance of sodium, low toxicity, and increased safety due to a lack of dendrite formation.…”

“…A further increase in performance was achieved by Wang et al., who used a layer‐by‐layer assembly technique with a porphyrin derivative as an interfacial linker to homogeneously attach SnO 2 crystals about 5 nm in size onto N and S codoped graphene . By combining it with a NVP/C cathode, a remarkable full‐cell capacity of 108.2 mAh g −1 was measured after 100 cycles at a rate of 0.1 A g −1 .…”

A Self‐Polymerized Nitro‐Substituted Conjugated Carbonyl Compound as High‐Performance Cathode for Lithium‐Organic Batteries

“…The b values are calculated to be 0.81 and 0.78 (Figure 3b), which are close to 1.0, indicatingt hat the capacitive process playsaleadingr ole in the Li storage in PT-2 NO 2 . [42] Meanwhile, the capacitive contribution at different scan rates can be quantified through the equation i = k 1 v + k 2 v 1/2 .C learly,t he capacitive contributioni ncreasesfrom 23.95 %t o7 3.09 %a sthe scan rate increases from 0.2 to 1mVs À1 (Figure 3c). These results indicatet hat Li storage in PT-2 NO 2 has ac apacitive mechanism,e specially at high rates.…”

High Areal Capacity Na0.67CoO2 Bundle Array Cathode Tailored for High‐Performance Sodium‐Ion Batteries

“…In general, the charge‐transfer resistance (R ct ) is the major segment in the whole resistance of electrode, which was calculated to be 236.7 and 38.4 Ω for the fresh and cycled cells (After 100 cycles at 1.4 C), manifesting the satisfied electronic conductivity and electrochemical stability of Na 0.67 CoO 2 cathode. The decreased charge transfer resistance might be ascribed to the enhanced electronic conductivity in the activation process for the initial 100 cycles …”