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We report a "solo-solvent de novo liquid-phase" method of synthesizing a highly-favored sulfide electrolyte (Li6PS5Cl) for developing all-solid-state lithium batteries. The key chemistry for such a successful method is that tetrahydropyrrole enables in situ synthesis of the critical precursor Li2S from cheap and air-stable precursors of lithium chloride and sodium sulfide. [ABSTRACT FROM AUTHOR]

Silicon is regarded as one of the most prospective anode candidates for the new generation of lithium ion batteries, because of its high theoretical specific capacity. Nevertheless, the huge expansion/contraction of silicon during cycling leads to rapid capacity decay. Herein, to suppress the concomitant mechanical damage, a composite material Si@B-C/rGO is prepared by in-situ encapsulating Si particles inside boron-doped carbon skeleton (B-C) and then loaded on reduced graphene oxide (rGO). The specific capacity of Si@B-C/rGO materials maintain at 1600 and 956 mAh g−1 after 100 cycles in liquid-phase and all-solid-state batteries, respectively. The performance improvement could be ascribed to main factors below: (i) The carbon shell significantly relieves expansion/contraction of silicon nanoparticles; (ii) The boron doping is conducive to the insertion/extraction of lithium-ions, because boron atoms have stronger affinity to lithium-ions than carbon; (iii) Loading Si@B-C nanoparticles on rGO can reduce particle agglomeration, and rGO provides a conductive network that ensures the transmission of lithium-ions. This work gives valuable reference to the design of advanced silicon-based anode materials to develop liquid and all-solid-state lithium-ion batteries. [Display omitted] • Si@B-C/rGO is prepared by in-situ encapsulating Si inside boron-doped carbon skeleton then loaded on reduced graphene oxide. • The introduction of boron into the carbon enhances Li+ adsorption and insertion behaviors, as verified by VASP calculations. • Loading Si@B-C nanoparticles on rGO can provides a conductive network that ensures the transmission of lithium-ions. • In liquid-phase and all-solid-state lithium-ion batteries, Si@B-C/rGO displays outstanding electrochemical performance. [ABSTRACT FROM AUTHOR]