Nitrogen-Doped Graphene-Supported Mixed Transition-Metal Oxide Porous Particles to Confine Polysulfides for Lithium-Sulfur Batteries
Nitrogen-Doped Graphene-Supported Mixed Transition-Metal Oxide Porous Particles to Confine Polysulfides for Lithium-Sulfur Batteries
复制标题
氮掺杂石墨烯负载混合过渡金属氧化物多孔颗粒限制锂硫电池中的多硫化物
DOI：
10.1002/aenm.201800595
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发表时间：
2018-08-06
影响因子：
27.8
通讯作者：
Xiong, Shenglin
中科院分区：
文献类型：
--
作者：
Sun, Qian;Xi, Baojuan;Xiong, Shenglin
硫的复杂充放电反应和较差的导电性决定了锂S电池正极工程的极端重要性。本文采用回流和水热相结合的方法制备了掺杂N的还原石墨烯氧化物尖晶石结构的锌钴酸锌多孔颗粒(ZnCo2O4@N-RGO)，它是由平均尺寸为5 nm的纳米立方体相互连接而成。首次得到的复合材料可以作为一种不可替代的阴极支架，通过锌和钴与硫之间的强化学键将锌钴氧化物和N-RGO化学限制在Li2S4上，从而抑制多硫化物的穿梭。RGO纳米片具有较高的比表面积，具有良好的导电网络和结构稳定性。掺杂N原子和大量的多孔纳米颗粒的引入可以抑制锂多硫化物在正负极之间的转移。由于独特的结构和组成特征，所获得的高硫负载量为71%甚至82%的杂化材料仍然具有高比容量、良好的倍率性能和增强的循环稳定性，具有非常高的初始库仑效率，这表明硫的利用率很高。
The intricate charge-discharge reactions and bad conductivity nature of sulfur determine the extreme importance of cathode engineering for Li-S batteries. Herein, spinel ZnCo2O4 porous particles@N-doped reduced graphene oxide (ZnCo2O4@N-RGO) are prepared via the combined procedures of refluxing and hydrothermal treatment, consisting of interconnected uniform ZnCo2O4 nanocubes with an average size of 5 nm anchored on graphene nanosheets. The as-obtained composite can act as an inimitable cathode scaffold to suppress the shuttling of polysulfides by chemical confinement of ZnCo2O4 and N-RGO for the first time, as demonstrated by the adsorption energy of ZnCo2O4 to Li2S4 via the strong chemical bonding between Zn or Co and S. The RGO nanosheets with a relatively high specific surface area provide a good conductive network and structural stability. The introduction of doped N atoms and numerous ZnCo2O4 porous nanoparticles can inhibit the transfer of lithium polysulfides between the cathode and anode. Due to the unique structural and compositional features, the as-obtained hybrid materials with the high sulfur loading of 71% and even 82% still deliver high specific capacity, good rate capability, and enhanced cycling stability with exceptionally high initial Coulombic efficiency, which displays a high utilization of sulfur.