钠电池的注液工艺是什么？

What is the liquid injection process for sodium-ion batteries?

注液是向密封空电芯精准定量注入电解液的核心工序，电解液作为离子传导介质，直接决定电池充放电能力。完整标准化流程：电芯高温真空烘干彻底除水、真空仓负压抽排内部空气、高精度计量泵定量加注电解液、恒温静置浸润让电解液充分浸透极片与隔膜微孔、按需二次补液后密封注孔。核心管控三大指标：真空度、注液计量精度、浸润静置时长。注液量不足会导致离子传导介质匮乏，电芯容量发挥不足，循环快速衰减；注液过量电芯内部预留空间不足，充放电产气后极易鼓包变形，提升材料成本。软包电芯预留封边用于二次注液，铝壳电芯注液孔焊接密封，全程无尘车间作业，微量杂质混入会持续加剧副反应，造成成品自放电超标，注液工序洁净度是电芯一致性关键管控点。

Liquid injection is the core procedure to inject quantitative electrolyte into sealed empty cells. As the ion transmission medium, electrolyte directly determines cell cycling capacity. The complete standardized flow includes high-temperature vacuum drying of cells for thorough dehumidification, negative-pressure air extraction in vacuum chambers, quantitative electrolyte injection by high-precision metering pumps, constant-temperature standing infiltration to fully soak electrodes and separator micropores, and secondary liquid supplement followed by sealing injection holes as needed. Three core controlled indicators are vacuum degree, injection metering precision and infiltration standing time. Insufficient electrolyte leads to lack of ion transmission medium, inadequate cell capacity and rapid cycle fading; excessive electrolyte leaves insufficient internal cell space, causing swelling deformation after gas generation during cycling and raising material costs. Soft packs reserve sealing edges for secondary liquid injection, while aluminum-shell cells weld injection holes for sealing. The whole procedure is carried out in dust-free workshops. Trace mixed impurities continuously aggravate side reactions and cause excessive self-discharge of finished cells, so cleanliness of liquid injection is a key control point for cell consistency.