A dual-confined nanostructured reactor, featured with the small-sized platinum nanoparticles embedded in dendritic mesoporous silica nanospheres with a hierarchical porous graphene-like carbon protection shell, is designed and synthesized as an efficient SeS2 host for high-performance lithium-selenium/sulfur batteries. The rationally designed host framework, which combines the merits of strong chemical interaction effect, abundant catalytic active sites, and excellent conducting network, can realize efficient anchoring and fast conversion of lithium polysulfides/polyselenides during the electrochemical processes. Thus, this SeS2-based cathode shows a high initial capacity of 1013 mAh g(-1) at 0.2 A g(-1) and an outstanding cycling stability, with a capacity of 426 mAh g(-1) over 500 cycles at 2 A g(-1), corresponding to a low capacity decay of 0.07% per cycle. This study demonstrates a novel and efficient approach to overcome the hurdles of current lithium-sulfur systems for stable rechargeable batteries. (C) 2021 Elsevier B.V. All rights reserved.