Three-in-one cathode host based on Nb3O8/graphene superlattice heterostructures for high-performance Li-S batteries
Three-in-one cathode host based on Nb3O8/graphene superlattice heterostructures for high-performance Li-S batteries
复制标题
DOI：
10.1039/d1ta01913a
复制
发表时间：
2021-03-29
影响因子：
11.9
通讯作者：
Sasaki, Takayoshi
中科院分区：
文献类型：
--
作者：
Wang, Chenhui;Sakai, Nobuyuki;Sasaki, Takayoshi
锂硫电池在下一代储能领域具有很高的应用前景。然而，进一步的进展受到各种棘手挑战的阻碍，特别是三个臭名昭著的问题：“穿梭效应”，多硫化锂转化的缓慢动力学和Li 2S的不均匀成核。在这项研究中，基于二维（2D）材料的超晶格的三合一阴极主机被设计来解决这三个问题。具有刘易斯酸表面的交替重新堆叠的Nb 3 O 8纳米片和具有高电导率的还原氧化石墨烯（rGO）产生了独特的超晶格结构，而没有自重新堆叠，从而最大化源于每个组分的固有优点的协同效应。Nb 3 O 8/rGO超晶格阴极主体的特征在于其高亲和力、优异的催化活性、丰富的暴露活性位点和高电导率，有效地限制了多硫化锂并降低了多硫化锂转化和Li 2S成核的过电位。其结果是，高性能的锂-硫电池，在0.1C下的初始容量为1529 mA h g（-1），并且在1C下在1000次循环中每个循环的容量衰减为0.064%。这项工作提供了一种异质组装2D纳米片作为阴极主体的新策略，为先进的锂硫电池开辟了一条有前途的途径。
Lithium-sulfur batteries have high promise for applications in next-generation energy storage. However, further advances have been hindered by various intractable challenges, particularly three notorious problems: the "shuttle effect", sluggish kinetics of lithium polysulfide conversion, and nonuniform nucleation of Li2S. In this study, a three-in-one cathode host based on a superlattice of two-dimensional (2D) materials is designed to tackle these three issues. Alternately restacked Nb3O8 nanosheets with Lewis acid surface and reduced graphene oxide (rGO) with high electrical conductivity give rise to a unique superlattice structure without the self-restacking, thereby maximizing the synergistic effect that stems from the inherent advantages of each component. The Nb3O8/rGO superlattice cathode host is characterized by its high affinity, excellent catalytic activity, abundance of exposed active sites, and high electrical conductivity, effectively confining lithium polysulfides and reducing the overpotentials for lithium polysulfide conversion and Li2S nucleation. As a result, high-performance lithium-sulfur batteries were achieved with an initial capacity of 1529 mA h g(-1) at 0.1C and a slow capacity decay of 0.064% per cycle at 1C over 1000 cycles. This work provides a novel strategy of heteroassembling 2D nanosheets as a cathode host, opening a promising avenue for advanced lithium-sulfur batteries.