A high-sulfur-loading cathode is the most essential component for lithium-sulfur batteries to gain considerable energy density for practical applications. The main challenges associated with high-sulfur-loading electrodes are low specific capacity caused by the insulating nature of sulfur and poor stability arising from dissolution of polysulfides into most organic electrolytes. Here, we propose a hierarchically structured sulfur cathode that simultaneously tackles both problems associated with high-sulfur-loading electrodes. Specifically, titanium monoxide hollow nanospheres are packed space efficiently and closely connected by carbon layers into microsized “clusters” as the sulfur host. As a result of this hierarchical structure design, the nanoscale reaction chambers and the microscale conductive networks cooperatively promise high capacities of sulfur at various current densities. During cycling, the titanium monoxide polar layer in every nanocompartment effectively hinders the dissolution of polysulfides, resulting in superior cycling stability for the high-sulfur-loading electrode.

高硫负载阴极是锂硫电池获得实际应用中相当大的能量密度所需的最基本组件。与高硫负载电极相关的主要挑战是由硫的绝缘性引起的低比容量和由于多硫化物溶解到大多数有机电解质中而引起的稳定性差。在这里，我们提出了一种层次结构化的硫阴极，可同时解决与高硫负载电极相关的两个问题。具体而言，一氧化钛中空纳米球被有效地堆积，并通过碳层紧密连接成微小的“团簇”作为硫主体。由于这种分层结构设计，纳米级反应室和微米级导电网络共同保证了各种电流密度下的高硫容量。在循环过程中，每个纳米隔室中的一氧化钛极性层有效地阻碍了多硫化物的溶解，从而为高硫负载电极带来了出色的循环稳定性。