CAJ | 학술논문

以不同温度、不同荷电态对锂离子电池进行储存实验,通过X射线衍射光谱法(XRD)和场发射扫描电子显微镜(FESEM)等手段研究了储存前后电极活性物质结构和表面形貌的变化;并对储存前后的电池进行测试,研究了储存对锂离子电池的容量、循环稳定性和安全性等综合性能的影响.结果发现,经不同荷电态高温储存后,锂离子电池正负极活性物质的体相结构没有发生变化,但其正极材料的微晶尺度和微应力随储存时荷电态的升高而减小;储存后,正极表面出现较明显的钝化膜,负极表面的固体电解质相界面(SEI)膜增厚.经高荷电态储存后,锂离子电池的交流内阻和厚度变大,1 C容量发生衰减,电极充放电极化增大,电池的1 C循环性能下降,安全性能下降;放电态储存后,电池的综合性能无明显变化.说明,放电态储存对于锂离子电池是一种较好的储存条件,有利于储存后电池综合性能的保持.
이불동온도、불동하전태대리리자전지진행저존실험,통과X사선연사광보법(XRD)화장발사소묘전자현미경(FESEM)등수단연구료저존전후전겁활성물질결구화표면형모적변화;병대저존전후적전지진행측시,연구료저존대리리자전지적용량、순배은정성화안전성등종합성능적영향.결과발현,경불동하전태고온저존후,리리자전지정부겁활성물질적체상결구몰유발생변화,단기정겁재료적미정척도화미응력수저존시하전태적승고이감소;저존후,정겁표면출현교명현적둔화막,부겁표면적고체전해질상계면(SEI)막증후.경고하전태저존후,리리자전지적교류내조화후도변대,1 C용량발생쇠감,전겁충방전겁화증대,전지적1 C순배성능하강,안전성능하강;방전태저존후,전지적종합성능무명현변화.설명,방전태저존대우리리자전지시일충교호적저존조건,유리우저존후전지종합성능적보지.
Lithium ion batteries were stored at elevated temperature in different state of charge(SOC). The structure and morphology of the electrode materials were investigated by means of XRD and FESEM, and the general performances of the batteries before and after storage were tested. The experimental results revealed that after storage at elevated temperature, the microcrystal and microstress of cathode material reduced as the storing SOC of batteries going up, though the bulk structures did not change. Meanwhile, during storage there deposited a passivation film on the surface of cathode as the SEI (solid electrolyte interface) film on the anode getting thicker. After stored in high SOC,the general performance of the batteries changed more obviously, including the fading of 1 C capacity, the deterioration of 1 C cycling performance, the degradation of safety performance and so on. However, the performance of the lithium ion batteries that were stored in low SOC condition didn't degrade. Therefore, it can be concluded that storage at low SOC condition is propitious to keep original general performance of lithium ion battery.