钠电池的电芯封装工艺有哪些？

What cell packaging processes are available for sodium-ion batteries?

电芯封装是裸芯隔绝空气、水汽、杂质的密封成型工序，主流分为圆柱钢壳、方形铝壳、软包铝塑膜三类路线，结构、性能、适配场景差异显著。第一圆柱钢壳封装：卷绕电芯装入钢制外壳，滚槽、激光封口成型，壳体坚固抗冲击，结构稳定，适合小型便携电源、路灯储能，缺点能量密度偏低。第二方形铝壳封装，适配卷绕、叠片两种裸芯，铝合金壳体导热散热性能最优，空间利用率高，配套防爆阀提升热安全冗余，是工商业大容量储能、电动叉车主流方案。第三软包铝塑膜封装，多层铝塑复合膜热压密封，重量轻、单体能量密度高，电芯胀气直观可见，无金属壳体爆炸风险，适配轻薄露营电源、小型户用储能。三类封装统一包含入壳、封口、真空检漏、整形四道基础工序，核心质控标准长期密封不漏液，杜绝水汽渗入破坏电解液体系。根据使用环境选型：户外大功率储能优先方形铝壳；便携小设备选用软包；低成本小型照明储能采用圆柱钢壳封装。

Cell packaging is a sealing forming procedure to isolate bare cells from air, moisture and impurities, with three mainstream routes of cylindrical steel shell, square aluminum shell and soft aluminum plastic film featuring distinct structures, performance and applicable scenarios. First, cylindrical steel shell packaging: winding bare cells are loaded into steel shells, shaped via rolling grooves and laser sealing. The rigid shell resists impact with stable structure, suitable for small portable power supplies and street lamp energy storage yet with low energy density. Second, square aluminum shell packaging fits both wound and stacked bare cells. Aluminum alloy shells deliver optimal heat conductivity and high space utilization, equipped with explosion-proof valves to boost thermal safety redundancy, the mainstream scheme for large-capacity industrial energy storage and electric forklifts. Third, soft aluminum plastic film packaging adopts hot-pressed multi-layer composite films, light in weight with high single-cell energy density, showing visible cell swelling without metal shell explosion risks, suitable for thin camping power and small household storage. All three packaging types share four basic procedures: shell loading, sealing, vacuum leakage inspection and shaping, with the core quality standard of long-term leakproof sealing to prevent moisture infiltration and electrolyte system damage. Selection depends on operating environments: square aluminum shells are prioritized for outdoor high-power storage, soft packs for portable small devices, cylindrical steel shells for low-cost small lighting storage.