Oh, Yunjae Lee, Hoseok Oh, Gwangeon Ryu, Seongje Kim, Un-Hyuck Jung, Hun-Gi Kim, Jongsoon Hwang, Jang-Yeon 2025-01-23T07:30:06Z 2025-01-23T07:30:06Z 2025-01-23 2025-02 0378-7753 https://pubs.kist.re.kr/handle/201004/151648 The Mn-based P3-type layered oxide (K0.5MnO2) is a promising cathode material for K-ion batteries (KIBs) because of its low cost, high specific capacity, and simple synthesis. However, it suffers from severe capacity loss and sluggish K+ diffusion kinetics, which are mainly attributed to multiple phase transitions and the Jahn-Teller distortion of Mn3+. To address these challenges, herein, the Mg and Cu co-substitution strategy is proposed to synthesize the P3-type K 0.5 Mn 0.8 Mg 0.1 Cu 0.1 O 2 (P3-KMMCO) as a cathode for KIBs. The presence of divalent Mg2+ and Cu2+ in the crystal structure of P3-KMMCO play the critical functions in regulating the Jahn-Teller-active Mn3+, thereby suppressing the complex phase transitions and improving the K+ diffusion kinetics during charging and discharging. As a result, the P3-KMMCO cathode demonstrates the high reversible capacity, outstanding cycling stability and power capability. A combination study of synchrotron-based X-ray analysis and first-principles calculations is used to validate the enhanced electrochemical K+ storage properties of the P3KMMCO cathode. English Elsevier BV Relaxation of the Jahn-Teller stress effect in the P3-type K0.5MnO2 cathode by copper and magnesium co-substitution for high-performance K-ion batteries Article 10.1016/j.jpowsour.2024.235786 1 Journal of Power Sources, v.628 Journal of Power Sources 628 N scie scopus 001395243000001 2-s2.0-85209679278 Chemistry, Physical Electrochemistry Energy & Fuels Materials Science, Multidisciplinary Chemistry Electrochemistry Energy & Fuels Materials Science Article LAYERED OXIDE ELECTRONIC-STRUCTURE POTASSIUM METALS K -ion batteries Cathode materials Jahn-Teller distortion High energy Co-substitution