What is the contact resistance of current collectors for sodium-ion batteries?

集流体接触电阻指活性涂层与铝箔界面阻抗，区别于铝箔本体电阻，是电芯总内阻关键组成。浆料涂布烘干后涂层贴合度、表面洁净度、有效接触面积直接决定该数值。接触电阻过高充放电界面大量发热，电压损耗上升，能量转换效率下降；长期持续高温造成涂层起皮掉粉，活性材料脱离铝箔，容量快速衰减。产生原因包含铝箔油污氧化、涂布厚度不均、辊压压力不足、粘结失效分层。工艺优化采用等离子清洗铝箔、精准辊压、高附着力粘结剂，缩小界面缝隙、扩大接触面积降低阻抗。大容量储能、电动叉车等高电流工况严格管控该参数，微小电阻差会造成整包温差、压差失衡，影响设备稳定运行。

Contact resistance of current collectors refers to the interfacial impedance between active coatings and aluminum foil, distinct from bulk aluminum resistance and a critical component of total cell resistance. Coating adhesion, surface cleanliness and effective contact area after coating and drying directly determine its value. Excessive contact resistance generates massive heat during cycling, raising voltage loss and lowering energy efficiency. Long-term high temperature causes coating peeling, detachment of active materials and rapid capacity fading. Root causes include oily oxidation on aluminum foil, uneven coating, insufficient calendering pressure and delaminated failed binders. Process optimizations include plasma cleaning, precise calendering and high-adhesion binders to narrow interfacial gaps, expand contact areas and cut impedance. High-current scenarios such as large-capacity energy storage and electric forklifts impose strict control; tiny resistance differences unbalance temperature and voltage across the whole battery pack and disrupt stable operation.