화학공학소재연구정보센터
학회 한국공업화학회
학술대회 2021년 봄 (05/12 ~ 05/14, 부산 벡스코(BEXCO))
권호 25권 1호
발표분야 포스터-환경·에너지
제목 Revealing the structural degradation mechanism of the Ni-rich cathode  surface: How thick is the surface?  
초록 We studied the structural degradation of Ni-rich NCM/graphite cylindrical 18650-type cells as a function of the cutoff voltage in the 4.2–4.4 V range. We verified that the phase changes continuously rather than discretely from the surface into the bulk through cation mixing. Our results suggest that the thickness of the phase-change region at the surface causes the battery performance to suddenly degrade at a certain value. We found that the deterioration in cell performance is mainly due to increasing diffusion resistance in the positive electrode. A 10–25 nm cation mixing layer wasobserved at the cathode surface after 300 cycles, and this surface layer thickened with increasing charging voltage. Further, simulations revealed that the cathode surface spontaneously evolves oxygen at higher electrochemical potentials.
저자 박광진1, 박광필2
소속 1가천대, 2도로교통공단
키워드 Li ion battyer; Cathode; Degradation
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