What are the approaches to improve the safety performance of sodium-ion batteries?

钠电池安全隐患来自热失控、内部短路、过充产气，优化覆盖材料、电解液、电芯结构、PACK 防护四层体系。一电极安全材料：优先聚阴离子高稳定正极，热分解温度超 500℃；改性硬碳抑制低温析钠，从源头降低热失控风险。二阻燃电解液体系：氟代、磷酸酯阻燃溶剂，搭配高压防过充添加剂，高温不易分解释氧，短路放热大幅减弱。三电芯内部防护：陶瓷复合隔膜提升抗穿刺能力；预留防爆阀、泄压封边，产气定向释放避免鼓包爆炸；极耳加厚防熔断短路。四 PACK 硬件   软件双重防护：BMS 多级过充、过放、过流、过温保护；高压保险丝、继电器硬件断路；全域 NTC 多点测温，单颗高温立即切断回路。五热管理隔离设计：电芯之间隔热泡棉、绝缘隔板，阻断热蔓延，防止连锁热失控。六生产质控升级：严控极片金属毛刺、粉尘，杜绝内部微短路源头；化成充分排出内部气体。七消防配套优化，密闭隔离舱设计。全链条协同改进后，针刺、挤压、热滥用测试不起火爆炸，满足工商业储能、船舶等高安全标准。

Safety hazards of sodium-ion batteries include thermal runaway, internal short circuit and gas generation from overcharge. Optimizations cover materials, electrolytes, cell structures and PACK protection. 1. Safe electrode materials: Adopt polyanion cathodes with thermal decomposition temperature above 500℃; modified hard carbon restrains sodium precipitation at low temperatures to eliminate thermal runaway risks at source. 2. Flame-retardant electrolytes: Fluorinated & phosphate solvents plus anti-overcharge additives resist high-temperature oxygen release and reduce heat release under short circuits. 3. Internal cell protection: Ceramic composite separators boost puncture resistance; reserved explosion-proof valves release gas to avoid swelling explosion; thickened tabs prevent fusion short circuits. 4. Dual PACK hardware & software protection: Multi-level BMS protection against overcharge, over-discharge, overcurrent and over-temperature; high-voltage fuses & relays cut circuits physically; full NTC multi-point temperature monitoring shuts down upon single-cell overheating. 5. Thermal isolation design: Thermal foam & insulating separators between cells block heat propagation and chain runaway. 6. Production QC upgrade: Strictly control metal burrs and dust to eliminate internal micro-short circuits; full gas exhaust during formation. 7. Optimized fireproof sealed isolation cabins. Full-chain improvements enable cells to pass nail penetration, extrusion and thermal abuse tests without fire or explosion, meeting high safety standards for industrial storage and marine equipment.