钠电池的内阻测试工艺是什么？

What is the internal resistance testing process for sodium-ion batteries?

内阻测试是电芯出厂必检质控工序，采用高频交流内阻测试仪检测电芯整体阻抗，反映离子传导、界面接触、内部结构完整度，区分良品与缺陷电芯。量产产线采用高频微电流快速检测模式，测试前电芯恒温静置消除温度、电压波动干扰，提升数据精准度。内阻数值直接映射电芯各类缺陷：内阻偏高大概率极片浸润不足、SEI 膜异常增厚、极片接触不良、内部微短路；同批次电芯内阻离散度过大，代表涂布、辊压制造一致性差。高倍率叉车、大功率储能 PACK 对内阻管控严苛，微小内阻差会造成模组局部发热集中，加速局部电芯衰减。内阻数据与分容数据绑定双重筛选不良电芯，内阻超标电芯直接报废，禁止流入 PACK 装配工序，从源头降低储能设备发热、压差过大故障概率。

Internal resistance testing is a mandatory factory quality control procedure for cells. High-frequency AC internal resistance testers detect overall cell impedance, reflecting ion conduction, interfacial contact and internal structural integrity to distinguish qualified and defective cells. Mass production lines adopt high-frequency micro-current rapid testing. Cells stand at constant temperature before testing to eliminate interference from temperature and voltage fluctuations and improve data accuracy. Internal resistance values directly reflect various cell defects: excessive resistance mostly results from insufficient electrode infiltration, abnormally thick SEI films, poor electrode contact and internal micro-short circuits. Excessive resistance dispersion of cells from the same batch indicates poor manufacturing consistency in coating and calendering. High-power forklifts and energy storage PACKs impose strict internal resistance control. Tiny resistance differences cause concentrated local heat generation in modules and accelerate local cell fading. Internal resistance data is bound with grading data for dual screening of defective cells. Cells with excessive resistance are directly scrapped and prohibited from entering PACK assembly, reducing heat and overvoltage difference faults of energy storage equipment from the source.