隔膜涂层对钠离子电池性能的影响

Effect of separators coating on the performance of sodium-ion battery

锂离子电池商用聚合物隔膜对钠离子电池电解液的润湿性差,商用陶瓷涂层隔膜(CCS)可解决浸润性差的问题。在纳米Al_(2)O_(3)陶瓷涂层的作用下,电解液能更好地被CCS吸收并透过CCS。CCS在150℃下搁置1.5 h后,收缩和变质程度比Celgard 2500基膜小,表明CCS的润湿性和热稳定性显著优于基膜。研究CCS对硬碳(HC)/Na_(3)V_(2)(PO_(4))_(3)(NVP)扣式电池电化学性能的影响,发现:CCS(7μm基膜+2μm涂层)涂层朝向负极侧时,电池以1.0 C在2.0~3.8 V循环100次的容量保持率为88.52%,5.0 C放电比容量为68.35 mAh/g,性能优于普通基膜(48.36%、40.86 mAh/g),表明Al_(2)O_(3)陶瓷隔膜在钠离子电池中具有应用潜力。

Commercial Li-ion battery polymer separators show poor wettability with the sodium-ion battery electrolyte.Commercial ceramic-coated separators(CCS)can solve the problem of poor wettability.Under the action of the nano Al 2O 3 ceramic coating,the electrolyte is better absorbed by the CCS and through the CCS.The shrinkage and deterioration degree of the CCS after shelving at 150℃for 1.5 h is smaller than that of the Celgard 2500 base separator,indicating that the CCS have better wettability and thermal stability than the base separator.The effect of CCS on the electrochemical performance of hard carbon(HC)/Na_(3)V_(2)(PO_(4))_(3)(NVP)button cell is studied,it is found that when the coating of CCS(7μm base separator+2μm coating)is towards the anode side,the capacity retention rate of battery is 88.52%after 100 cycles at 1.0 C in 2.0-3.8 V,the specific discharge capacity at 5.0 C is 68.35 mAh/g,the performance is better than that of the ordinary base separator(48.36%,40.86 mAh/g).It shows that Al_(2)O_(3)ceramic separators has application potential in sodium-ion battery.