钠电池卷绕和叠片工艺的核心区别是什么？

What are the core differences between winding and stacking processes of sodium-ion batteries?

卷绕与叠片是两类电芯成型工艺，四大维度存在根本性差异。第一结构应力：卷绕电芯圆心持续拉伸应力集中，长期循环局部形变严重；叠片全部平铺无拉伸，每层受力均匀，结构稳定性更强。第二电化学性能：叠片散热通道多，大功率温升低、循环寿命长、模组压差小；卷绕电芯散热差，大电流工况发热明显，容量衰减速度更快。第三生产效率与成本：卷绕自动化产线速度快、设备投入低，适合大批量平价电芯量产；叠片机械手堆叠效率低，设备、人工成本上浮 10%~20%，仅用于高端产品。第四适配场景：卷绕适配 100Ah 以内小型电芯，太阳能路灯、户用储能、两轮电动车；叠片适配 200Ah 以上大容量工商业储能、电网储能、重型叉车，对循环寿命、安全等级要求严苛。现阶段市场量产低端储能以卷绕为主，大型长时储能项目逐步普及叠片工艺，项目投资方根据容量、寿命预算选型匹配对应成型方案。

Fundamental differences exist between winding and stacking processes in four dimensions. First, structural stress: winding cells suffer concentrated tensile stress at the core with severe local deformation during long cycling; all stacked electrodes are laid flat without tension and bear uniform force for stronger structural stability. Second, electrochemical performance: stacked cells feature abundant heat dissipation channels, low temperature under high power, long cycle life and small module voltage difference, while winding cells deliver poor heat dissipation, obvious heat generation under large current and faster capacity fading. Third, production efficiency and cost: automated winding lines operate fast with low equipment investment for mass production of low-cost cells; manipulator stacking has low efficiency with 10%~20% higher equipment and labor costs only for high-end products. Fourth, applicable scenarios: winding fits small cells below 100Ah for solar street lamps, household storage and two-wheelers; stacking targets large-capacity industrial & commercial energy storage, grid storage and heavy forklifts above 200Ah with strict cycle and safety requirements. At present, winding dominates mass production of low-end energy storage, while stacking is gradually popularized for large long-duration storage projects. Investors select corresponding forming schemes according to capacity and life budget.