We will discuss about applying ‘materials by design’ and validation experimental research on high capacity cathode materials for Li and Na ion batteries (LIB and NIB). Using the first-principles density functional theory (DFT) method, we have designed electrode materials for battery cathodes, and subsequently performed experimental studies to validate the material designs. Through an integrated material design - experiment research, we have developed highly efficient cathode materials for NIB. [1] Furthermore, using the DFT based stability analysis of Li(Ni,Mn,Co)O₂ (NMC) cathode materials, the underlying mechanisms of stability change in Ni-rich NMC cathodes are elucidated over the range of 30 – 100 % Ni concentration in metal composition. [2-6] Surface analysis of Ni-rich NMC has also provided insights on the degradation mechanisms (both chemical and mechanical) facilitating to develop a design strategy to improve the stability of Ni-rich NMC over 80% Ni contents. [7]

This work was also supported by the International Energy Joint R & D Program (No. 20168510011350) of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Ministry of Knowledge Economy, Korean government.

[1] D. Kim, M. Cho, K. Cho, “Rational Design of Na(Li1/3Mn2/3)O-2 Operated by Anionic Redox Reactions for Advanced Sodium-Ion Batteries,” Adv Mater 29(33), 1701788 (2017).

[2] Chaoping Liang, F, Kong, R. Longo, Santosh KC, Jeom-Soo Kim, SangHoon Jeon, SuAn Choi, K. Cho, “Unraveling the Origin of Instability in Ni-Rich LiNi_1−2xCo_xMn_xO₂ (NCM) Cathode Materials,” The Journal of Physical Chemistry C 120(12), 6383–6393 (Mar. 31, 2016)

[3] R. C. Longo, F. Kong, C. Liang, D. -H. Yeon, J. Yoon, J. -H. Park, S. -G. Doo and K. Cho, “Transition Metal Ordering Optimization for High-Reversible Capacity Positive Electrode Materials in the Li-Ni-Co-Mn Pseudoquaternary System,” Journal of Physical Chemistry C 120(16), 8540-8549 (Apr. 28, 2016).

[4] F. Kong, C. Liang, L. C. Roberto, D.-H. Yeon, Y. Zheng, J.-H. Park, S.-G. Doo and K. Cho, “Conflicting Roles of Anion Doping on the Electrochemical Performances of Li-ion Battery Cathode Materials”, Chem. Mater. 28(19), 6942–6952 (Oct. 11, 2016)

[5] Chaoping Liang, Roberto C. Longo, Fantai Kong, Chenxi Zhang, Yifan Nie, Yongping Zheng, Jeom-Soo Kim, SangHoon Jeon, SuAn Choi, and K. Cho, “Obstacles toward unity efficiency of LiNi1-2xCoxMnxO2 (x=0~1/3) (NCM) cathode materials: Insights from ab initio calculations” Journal of Power Source 340, 217-228 (2017).

[6] C. Liang, F. Kong, R. Longo, C. Zhang, Y. Nie, Y. Zheng, K. Cho, “Site-dependent multicomponent doping strategy for Ni-rich LiNi1-2yCoyMnyO2 (y=1/12) cathode materials for Li-ion batteries,” J. Mater. Chem. A 5(48), 25303-25313 (Dec. 2017).

[7] C. Liang, R. Longo, F. Kong, C. Zhang, Y. Nie, Y. Zheng, K. Cho, “Ab initio Study on Surface Segregation and Anisotropy of Ni-rich LiNi_1-2yCo_yMn_yO₂ (NCM) (y ≤ 0.1) Cathodes,” ACS Appl. Mater. Inter. (2018).