Atomic Layer Deposition-Assisted Construction of Binder-Free Ni@N-Doped Carbon Nanospheres Films as Advanced Host for Sulfur Cathode.

Rational design of hybrid carbon host with high electrical conductivity and strong adsorption toward soluble lithium polysulfides is the main challenge for achieving high-performance lithium-sulfur batteries (LSBs). Herein, novel binder-free Ni@N-doped carbon nanospheres (N-CNSs) films as sulfur host are firstly synthesized via a facile combined hydrothermal-atomic layer deposition method. The cross-linked multilayer N-CNSs films can effectively enhance the electrical conductivity of electrode and provide physical blocking "dams" toward the soluble long-chain polysulfides. Moreover, the doped N heteroatoms and superficial NiO layer on Ni layer can work synergistically to suppress the shuttle of lithium polysulfides by effective chemical interaction/adsorption. In virtue of the unique composite architecture and reinforced dual physical and chemical adsorption to the soluble polysulfides, the obtained Ni@N-CNSs/S electrode is demonstrated with enhanced rate performance (816 mAh g at 2 C) and excellent long cycling life (87% after 200 cycles at 0.1 C), much better than N-CNSs/S electrode and other carbon/S counterparts. Our proposed design strategy offers a promising prospect for construction of advanced sulfur cathodes for applications in LSBs and other energy storage systems.