钠电池化成工艺的核心作用是什么？

What are the core functions of the formation process for sodium-ion batteries?

化成工艺具备四大核心作用，奠定电芯长期稳定循环基础。第一可控界面成膜，通过初次温和充放电，在正负极构建均匀致密 SEI/CEI 钝化膜，大幅降低后续循环电解液不可逆损耗，延缓容量衰减；第二完全激活电极活性物质，打开全部钠离子传输通道，释放电芯额定设计容量，消除前期容量虚低现象；第三提前排出化成阶段电解液分解产生的微量气体，防止电芯内部积气鼓包，稳定内部压力；第四前置缺陷筛查，化成阶段实时监测电压、温度，微短路、浸润不足、封装漏液电芯参数异常，提前分离报废，减少终端储能设备故障概率。长时储能产品延长恒温静置时间，进一步优化钝化膜稳定性，模组长期运行压差更小。化成是决定电池循环寿命、一致性的关键后处理工序，各大电芯厂针对自身材料体系定制专属化成电流、温度曲线优化产品综合性能。

The formation process has four core functions laying the foundation for long-term stable cell cycling. First, controllable interfacial film formation: mild initial cycling builds uniform compact SEI/CEI passivation films on electrodes, drastically cuts irreversible electrolyte loss during subsequent cycling and slows capacity fading. Second, full activation of electrode active materials: all sodium ion transmission channels are opened to release rated designed cell capacity and eliminate early insufficient capacity. Third, advance exhaust of trace gas generated by electrolyte decomposition during formation to prevent internal gas accumulation and cell swelling and stabilize internal pressure. Fourth, pre-defect screening: real-time monitoring of voltage and temperature during formation identifies cells with micro-short circuits, poor infiltration and packaging leakage via abnormal parameters for early scrapping and lower failure probability of terminal energy storage equipment. Long-duration energy storage products extend constant-temperature standing time to further optimize passivation film stability and reduce module voltage difference during long-term operation. Formation is a key post-treatment procedure determining cell cycle life and consistency. Each cell manufacturer customizes exclusive formation current and temperature curves for its own material systems to optimize comprehensive product performance.