ScholarWorks@성균관대학교

초록

All-solid-state batteries (ASSBs) suffer from poor interfacial adhesion betweenthe Ni-rich NCM cathode and conventional coatings (CCs) such as LiNbO3, resulting in poor rate- and cycle-performances. Through firstprinciples calculations, we identify that the interfacial adhesion is weakened during the delithiation process, which can lead to coating exfoliation and direct contact with the sulfide-based solid electrolyte. To address this issue, we design a cathode-adhesion-enhanced coating (CAEC) that strengthens bonding interactions and oxygen affinity within the crystal structure of the conventional coating, LiNbO3. CAEC also provides a lower activation barrier for Li+ transport and a wider electrochemical potential window than the CCs, indicating CAEC not only enhances cycle-performances but also improves power-capability and high-voltage operation stability. As a result, CAEC-applied ASSBs deliver highly enhanced initial Coulombic efficiency, power-capability and cycleperformance compared to CC-applied ASSBs. Furthermore, in terms of cycle-performance, CAEC-applied ASSBs not only maintain their capacity but also exhibit reduced voltage-decay, demonstrating a clear advantage in retaining energy density during prolonged cycling. The application of CAEC effectively and stably suppresses interfacial side reactions between the sulfide-based solid electrolyte and the Ni-rich NCM cathodes during prolonged cycling, highlighting its significant advantage in mitigating the intrinsic degradation issues of ASSBs.

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