Suppressing Surface Degradation in Na‐Rich Prussian Blue Cathodes via Liquid‐Phase Dehydration
Abstract
ABSTRACT Na‐rich Prussian Blue (PB) is an attractive sodium‐ion battery cathode owing to its high capacity and low cost, yet approximately 10 wt.% of crystal water in its framework induces electrolyte side reactions and Fe dissolution. Conventional thermal dehydration has been used to remove crystal water, but it consistently results in capacity fading and poor air stability. Here, the primary cause of degradation is experimentally demonstrated to be surface oxidation driven by Fe–O bond formation during heat treatment. Guided by this insight, a liquid‐phase, low‐temperature dehydration strategy based on nitrogen bubbling is introduced, which simultaneously eliminates crystal water and stabilizes the surface. The approach can be seamlessly integrated into electrode fabrication to minimize air exposure and improve cycling stability. Overall, this work clarifies the mechanistic role of surface oxidation in moisture‐sensitive PB cathodes and highlights the critical importance of surface chemistry control in achieving stable electrochemical performance.
Article Details
Authors (9)
Seunghye Jang
Department of Battery Engineering Graduate Institute of Ferrous & Eco Materials Technology Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk Republic of Korea
Hyebin Jeong
Department of Chemical Engineering Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk Republic of Korea
Jun Choi
2NYU Langone Health, Perlmutter Cancer Center, Medical Oncology and Hematology, New York, United States
Jeongsoo Hong
Department of Chemical Engineering Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk Republic of Korea
Jooyoung Jang
Department of Battery Engineering Graduate Institute of Ferrous & Eco Materials Technology Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk Republic of Korea
Jongyoon Han
Juwon Kim
Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
Sang‐Min Lee
Department of Battery Engineering Graduate Institute of Ferrous & Eco Materials Technology Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk Republic of Korea
Changshin Jo
Department of Battery Engineering Graduate Institute of Ferrous & Eco Materials Technology Pohang University of Science and Technology (POSTECH) Pohang Gyeongbuk Republic of Korea