| 학회 |
한국재료학회 |
| 학술대회 |
2020년 가을 (11/18 ~ 11/20, 휘닉스 제주 섭지코지) |
| 권호 |
26권 1호 |
| 발표분야 |
C. 에너지 재료 분과 |
| 제목 |
High-voltage-induced surface structuring and electrochemical stabilization of Ni-rich layered cathode materials for Li-ion batteries |
| 초록 |
Layered lithium–nickel–cobalt–manganese oxide (NCM) materials have emerged as promising alternative cathode materials owing to their high energy density and electrochemical stability. Although the reversible capacity of Ni-rich NCM electrode materials has been improved by introducing Ni and Mn to LiCoO2, complete lithium extraction from NCM electrodes remains challenging because of the irreversible structural transition and electrolyte decomposition occurring at high cut-off voltage, which result in safety issues and poor cycle performance. Herein, we present the unexpected realization of sustained working voltage as well as improved electrochemical performance upon electrochemical cycling at a high operating voltage of 4.9 V in the Ni-rich NCM LiNi0.895Co0.085Mn0.02O2. The improved electrochemical performance at high working voltage at 4.9 V is attributed to the removal of the resistive Ni2+O rock-salt surface layer, which stabilizes the voltage profile and improves retention of the energy density during electrochemical cycling. The manifestation of the layered Ni2+O rock-salt phase along with the structural evolution related to the metal dissolution are probed using in-situ X-ray diffraction, neutron diffraction, transmission electron microscopy, and X-ray absorption spectroscopy. Our findings help unravel the structural complexities associated with high working voltage and offer insight for the design of advanced battery materials, enabling the realization of fully reversible lithium extraction in Ni-rich NCM materials. |
| 저자 |
송석현1, 조모세2, 박인철1, 유종규3, 고경태4, 홍지현5, 김종순6, 정성균7, Maxim Avdeev8, 지성대9, 이성수10, 방준하1, 김형섭1
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| 소속 |
1한국원자력(연), 2고려대, 3포항산업과학(연), 4포항공과대, 5Max Planck POSTECH/Korea Research Initiative, 6한국기초과학지원(연), 7한국과학기술(연), 8세종대, 9삼성종합기술원, 10ANSTO |
| 키워드 |
Cathodes; Li-ion batteries; Ni-rich NCM; High voltage; Surface stabilization
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| E-Mail |
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