Dendrite-suppressing Li–S batteries through triple-component polymer electrolyte design

Lithium-sulfur (Li–S) batteries are considered as one of the most promising next-generation energy storage devices. However, due to the high working current density and the shuttle of polysulfides, a large number of dendrites and corrosion are formed on Li anode, restricting the wide application of Li–S battery. Herein, a triple-component gel polymer electrolyte (PHMA) comprising poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)–polyacrylonitrile (PAN)–polymethyl methacrylate (PMMA) is developed, the excellent processability and Li ion conductivity of PVDF-HFP, the excellent polysulfide adsorption capability of PAN and the excellent wettability of PMMA are significantly enhanced after compositing, then uniform Li ions deposition is regulated and the growth of Li dendrite is greatly suppressed. In addition, the shuttle effect of polysulfides is greatly suppressed through physical, chemical and weak hydrogen bonding adsorption provided by the diversification of polar groups. Given these advantages, an ionic conductivity of 4.0 × 10 –3  S cm −2 is achieved and a minor polarization voltage of 15 mV is exhibited for Li//Li cell after 1000 h cycling, in situ optical microscope-electrochemical cell further robustly confirms the enhanced stability of Li foil. As a result, S/PHMA/Li battery delivers stable cycling performance with a capacity decay of 0.5% per cycle after 100 cycles at 0.2 C. Graphical