什么是钠电池的循环寿命测试？

What is the cycle life test for sodium-ion batteries?

循环寿命是评估电池全生命周期耐用核心长时试验，按照国标标准 0.2C 充放电完整循环，每 50 圈记录容量、内阻、电压平台衰减数据，直至容量降至初始 80% 终止，总循环次数即为寿命指标。试验恒温 25℃标准环境，充电至额定电压静置 30 分钟，放电至截止电压静置 1 小时为完整一圈。循环过程 SEI/CEI 膜持续增厚、活性材料缓慢粉化，容量逐步下滑。聚阴离子钠电池可达 4000~6000 次循环，普鲁士蓝约 3000 次，层状氧化物 2500 次左右。测试全程同步记录模组压差、温升，用于评估材料、极片工艺、PACK 均衡方案优劣。储能电站采购电芯强制要求提供完整循环寿命报告，循环寿命不达标产品运维更换成本极高。

Cycle life is a long-term core test evaluating full battery durability. Conduct complete 0.2C charge-discharge cycles per national standard, record capacity, internal resistance and voltage fading every 50 cycles until capacity drops to 80% of initial value; total cycles equal the life index. Standard constant 25℃ environment: charge to rated voltage, rest 30 minutes, discharge to cut-off voltage and rest 1 hour as one full cycle. SEI/CEI films continuously thicken and active materials slowly pulverize during cycling with gradual capacity decline. Polyanion sodium batteries reach 4000~6000 cycles, Prussian blue around 3000, layered oxides roughly 2500. Simultaneously record module voltage difference and temperature rise throughout testing to evaluate advantages of materials, electrode processes and PACK balancing schemes. Energy storage power station procurement mandates complete cycle life reports; products failing this test carry extremely high operation & replacement costs.