Rational Design of a Dual-Function Hybrid Cathode Substrate for Lithium-Sulfur Batteries
Rational Design of a Dual-Function Hybrid Cathode Substrate for Lithium-Sulfur Batteries
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DOI：
10.1002/aenm.201801014
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发表时间：
2018-08-27
影响因子：
27.8
通讯作者：
Manthiram, Arumugam
中科院分区：
文献类型：
--
作者：
Luo, Liu;Chung, Sheng-Heng;Manthiram, Arumugam
通过生物分子辅助自组装合成，将具有化学耦合二硫化镍还原氧化石墨烯（NiS2-RGO）框架的独特3D混合海绵合理地开发为有效的多硫化物储库。具有多孔纳米花状形态的优化量的 NiS2（约 18 wt%）均匀地原位生长在 RGO 基底上，提供丰富的活性位点来吸附和定位多硫化物。实验数据和第一原理计算证实了亲硫 NiS2 改善的多硫化物吸附性。此外，由于原位合成过程中形成的NiS2和RGO之间的化学耦合，导电RGO基底提供了3D电子路径，促进电荷向NiS2-多硫化物吸附界面转移，引发多硫化物转化的快速氧化还原动力学和优异的倍率性能（C/20-4C）。因此，自组装杂化结构同时提高了静态多硫化物捕获能力和动态多硫化物转化可逆性。因此，3D多孔海绵具有高硫含量（75 wt%）、极高的硫负载量（高达21 mg cm(-2)）和面积容量（高达16 mAh cm(-2)），超过了涉及RGO或金属硫化物/其他金属化合物的文献中大多数报道的值（硫含量为
A unique 3D hybrid sponge with chemically coupled nickel disulfide-reduced graphene oxide (NiS2-RGO) framework is rationally developed as an effective polysulfide reservoir through a biomolecule-assisted self-assembly synthesis. An optimized amount of NiS2 (approximate to 18 wt%) with porous nanoflower-like morphology is uniformly in situ grown on the RGO substrate, providing abundant active sites to adsorb and localize polysulfides. The improved polysulfide adsorptivity from sulfiphilic NiS2 is confirmed by experimental data and first-principle calculations. Moreover, due to the chemical coupling between NiS2 and RGO formed during the in situ synthesis, the conductive RGO substrate offers a 3D electron pathway to facilitate charge transfer toward the NiS2-polysulfide adsorption interface, triggering a fast redox kinetics of polysulfide conversion and excellent rate performance (C/20-4C). Therefore, the self-assembled hybrid structure simultaneously promotes static polysulfide-trapping capability and dynamic polysulfide-conversion reversibility. As a result, the 3D porous sponge enables a high sulfur content (75 wt%) and a remarkably high sulfur loading (up to 21 mg cm(-2)) and areal capacity (up to 16 mAh cm(-2)), exceeding most of the reported values in the literature involving either RGO or metal sulfides/other metal compounds (sulfur content of