Low-Cost Preparation of High-Performance Na-B-H-S Electrolyte for All-Solid-State Sodium-Ion Batteries

All-solid-state sodium-ion batteries have the potential to improve safety and mitigate the cost bottlenecks of the current lithium-ion battery system if a high-performance electrolyte with cost advantages can be easily synthesized. In this study, a one-step dehydrogenation-assisted strategy to synthesize the novel thio-borohydride (Na-B-H-S) electrolyte is proposed, in which both raw material cost and preparation temperature are significantly reduced. By using sodium borohydride (NaBH 4 ) instead of B as a starting material, B atoms can be readily released from NaBH 4 with much less energy and thus became more available to generate thio-borohydride. The synthesized Na-B-H-S (NaBH 4 /Na-B-S) electrolyte exhibits excellent compatibility with current cathode materials, including FeF 3 (1.0–4.5 V), Na 3 V 2 (PO 4 ) 3 (2.0–4.0 V), and S (1.2–2.8 V). This novel Na-B-H-S electrolyte will take a place in mainstream electrolytes because of its advantages in preparation, cost, and compatibility with various cathode materials.