钠电池热失控的防护措施有哪些？

What protective measures are available against thermal runaway of sodium-ion batteries?

钠电池热失控防护采用 “源头预防 - 过程管控 - 事故阻隔” 三层完整防护体系，从电芯、PACK 储能系统、储能舱三个层级配套多重防控手段，全方位降低起火连锁风险。电芯级源头防护为第一道防线：选用聚阴离子等高热稳定正极、优化耐温电解液与陶瓷涂覆隔膜，从材料层面抬高热失控触发温度；生产环节严控极片毛刺、隔膜破损，高精度化成分容剔除缺陷电芯；匹配高精度 BMS 芯片，实时监控单串电压、电流、温度，超过充放电阈值立即切断回路，杜绝过充过放、短路等电气滥用诱因。PACK 级过程管控为第二道防护：电芯之间铺设隔热阻燃泡棉，预留标准化散热风道，避免热量相互传导；汇流排加厚抗氧化处理，降低接触发热；每串独立温度采集探头，单芯超温即启动风冷散热，严重异常自动断开高压总闸；采用阻燃外壳与密封胶条，阻挡电解液外泄蔓延火情，搭配均衡算法控制单串压差，防止单体超前老化引发局部过热。储能舱 / 电站级事故阻隔为第三道防线：储能舱分区隔离布置电池簇，簇间设置防火隔墙与隔热通道；配套 24 小时温感、烟感探测报警系统，温度异常提前预警；集成专用干粉 / 全氟己酮自动灭火装置，检测到火情瞬间喷射阻燃介质快速降温窒息火焰；强制机械通风系统持续置换舱内可燃气体，控制内部气体浓度低于爆炸下限。配套运维管理防护：制定季度电芯压差、温度巡检制度，及时更换老化电芯；严格规范运输、装卸流程，避免挤压穿刺机械损伤；控制储能舱环境温度常年维持 20-35℃，杜绝长期高温静置。多层防护协同作用，既能大幅降低热失控触发概率，即便单一电芯故障，也能阻隔火情扩散，保障储能系统整体安全运行。

A three-layer protection system consisting of source prevention, real-time control and accident isolation is adopted to curb sodium-ion thermal runaway across cell, PACK and storage cabin levels. Cell-level source prevention (first barrier): adopt high thermal-stability polyanionic cathodes, high-temperature resistant electrolyte and ceramic coated separators to raise runaway trigger temperature via material optimization. Strictly control electrode burrs and separator defects during production, screen defective cells via precise formation and grading. High-precision BMS monitors single-string voltage, current and temperature to cut circuits immediately once crossing charge-discharge limits and eliminate electrical abuse risks. PACK-level real-time control (second barrier): lay flame-retardant thermal insulation foam between cells with standardized cooling channels to stop heat transfer. Thickened anti-oxidation busbars reduce contact heat. Independent temperature sensors per string activate forced air cooling upon overheating and cut high-voltage main switches under severe faults. Flame-retardant housings and sealants block electrolyte leakage and fire spread. Equalization algorithms control string voltage difference to avoid local heat from premature aging. Cabin/station accident isolation (third barrier): battery racks are separated by fire partition walls with heat insulation aisles. 24-hour temperature & smoke sensors provide early warning. Automatic dry powder / FK-511 fire suppression systems spray flame retardants instantly to cool and suffocate fires. Forced ventilation continuously dilutes flammable gas below explosion limits. Auxiliary operation protection: quarterly inspections of cell voltage and temperature replace aged units; standardized transportation & handling rules prevent squeeze and puncture; maintain cabin temperature at 20-35℃ to avoid long-term high-temperature storage. Coordinated multi-layer measures drastically reduce runaway probability and contain fire spread even if single cell fails to guarantee overall storage system safety.