储能用钠离子电池及电池模块的开发应用

Development and application of sodium-ion battery and module for energy storage system

设计了一款储能用电池模块,模块采用新型钠离子电池,具有较高的充放电能量效率、宽温域放电性能、倍率性能好、长循环、高安全等优点。经测试,单体电芯0.33 C充放电能量效率为97.18%,-40℃下1 C放电容量为常温容量的89.79%,5 C放电容量为0.33 C容量的90.49%,40℃下30天存储后恢复容量保持率为98.34%,0.5 C下常温循环2000次后容量保持率为86.65%,可顺利通过过充、挤压、针刺、过放、短路等安全测试;电池模块在25℃、0.33 C充放电条件下,能量效率为96.3%;在25℃、0.33P充放电条件下,能量效率为95.75%;在5℃、0.33P充放电条件下,与25℃条件下测试相比,能量效率为90.08%。该模块采用风冷散热,模块内电芯温差可控制在3℃以内,可满足储能系统要求。

A new type of sodium-ion battery and module was designed for the large-scale energy storage system,having the advantages of high charge and discharge energy conversion efficiency,wide temperature range discharge ability,good rate performance,long cycle and high safety.The charge and discharge energy efficiency of a single cell is 97.18%at 0.33 C,and the discharge capacity at 1 C and-40℃is 89.79%of the capacity at 25℃.The discharge capacity at 5 C is 90.49%of the capacity at 0.33 C.After storing at 40℃for 30 days,the single cell delivers a high reversible capacity retention of 98.34%.The capacity retention reaches 86.65%after cycling at 0.5 C and 25℃,and the single cell can successfully pass the safety tests of overcharge,extrusion,nail penetration,over discharge and short circuit.The energy efficiency of the battery module is 96.3%at 0.33 C and 25℃,and the energy efficiency is 95.75%at 0.33P and 25℃.The energy efficiency is 90.08%at 0.33P and 5℃.The heat dissipation of the battery module is based on the air cooling.The temperature difference of the battery module is within 3℃,meeting the requirements of the energy storage system.