Conformal Buffer Layer Coating on Ni-Rich Cathode Powder via Particle Atomic Layer Deposition for All-Solid-State Batteries

While all-solid-state batteries (ASSBs) have received considerable attention as next-generation energy storage devices, the problems that arise between the cathodes and solid-state electrolytes (SSEs) of ASSBs have been regarded as among the greatest technical issues related to ASSBs, and several studies have been conducted to address these issues. A stable oxide buffer layer coating on the interface between the cathode active material (CAM) and the SSE is known to be effective in suppressing side reactions at the interface, including space charge layer formation and SSE decomposition. To achieve this, it is essential to coat a uniform and conformal buffer layer on the CAM surface. In this study, a powerful technique for conformal coating on a particle, called particle atomic layer deposition (ALD), was introduced to produce the buffer layer coating on CAM particles. The introduction of particle ALD to the energy technology was studied, and the synthesis of ternary materials through particle ALD was demonstrated for the first time. The results show that a buffer layer fabricated by particle ALD is effective in suppressing side reactions and enhancing the performance of ASSBs.