Lightweight Free-Standing 3D Nitrogen-Doped Graphene/TiN Aerogels with Ultrahigh Sulfur Loading for High Energy Density Li-S Batteries
Lightweight Free-Standing 3D Nitrogen-Doped Graphene/TiN Aerogels with Ultrahigh Sulfur Loading for High Energy Density Li-S Batteries
复制标题
用于高能量密度锂硫电池的具有超高硫负载的轻质独立式 3D 氮掺杂石墨烯/TiN 气凝胶
DOI：
10.1021/acsaem.1c00880
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发表时间：
2021-07-20
影响因子：
6.4
通讯作者：
Rao, Huashang
中科院分区：
文献类型：
--
作者：
Cheng, Qi;Yin, Zhouhong;Rao, Huashang
锂硫电池以其较高的理论比容量和高能量密度而受到广泛关注。然而，大多数已报道的锂硫电池的硫负荷和硫含量较低，导致其实际能量密度较低。本文设计并制备了基于独立三维（3D）氮掺杂石墨烯/TiN复合气凝胶（3DNG-TiN）的无粘结剂和无金属集流器的轻质电极，用于组装高能量密度Li-S电池。气凝胶中的三维网络结构提供了优良的电荷传输通道和大的微孔和亚微米孔，以确保超高的硫负载。值得注意的是，复合材料中的极性TiN纳米颗粒组分有效抑制了穿梭效应，加速了多硫化物的反应动力学，显著提高了锂硫电池的循环性能和倍率性能。此外，轻质独立的3DNG-TiN电极（3.54 mg/cm(2)）将阴极中的绝对硫含量提高到85.0% wt %。高硫负载（20.0 mg/cm(2)）的锂硫电池在2.0 mA/cm(2)下循环100次后，显示出18.9 mA h/cm(2)和16.2 mA h/cm(2)的高初始面积容量。这项工作为实现锂硫电池的高能量密度提供了一种新的策略。
Lithium-sulfur (Li-S) batteries have attracted extensive attention due to their high theoretical specific capacity and high energy density. However, the sulfur loading and sulfur content are low in most of the reported Li-S batteries, resulting in a low practical energy density. Herein, binder- and metal-current-collector-free lightweight electrodes based on a free-standing three dimensional (3D) nitrogen-doped graphene/TiN composite aerogel (3DNG-TiN) are designed and prepared to assemble high energy density Li-S batteries. The 3D network structure in the aerogel provides excellent charge transport channels and large microand submicron pores to ensure an ultrahigh sulfur loading. Notably, the polar TiN nanoparticle component in the composite effectively suppresses the shuttling effect and accelerates the reaction kinetics of polysulfides, which significantly enhances the cycling and rate performance of resulting Li-S batteries. Additionally, the lightweight free-standing 3DNG-TiN electrode (3.54 mg/cm(2)) boosts the absolute sulfur content in the cathode up to 85.0 wt %. Li-S batteries with a high sulfur loading (20.0 mg/cm(2)) exhibit high initial areal capacities of 18.9 mA h/cm(2) and 16.2 mA h/cm(2) after 100 cycles at 2.0 mA/cm(2). This work provides a new strategy to achieve a high energy density of Li-S batteries.