(Invited) Redefined Battery Science and Engineering after 100 Years of Debye-Hückel Theory

In any electrochemical system, electrode potential is the central variable that regulates the driving force of redox reactions. However, quantitative understanding of the electrolyte dependence has been limited to the classic Debye-Hückel theory that approximates the Coulombic interactions in the electrolyte under the dilute limit conditions. Therefore, accurate expression of electrode potential for most of practical electrochemical systems has been a holy grail of electrochemistry research for over a century. Here we show that the ‘liquid Madelung potential’ based on the conventional explicit treatment of solid-state Coulombic interactions enables quantitatively accurate expression of the electrode potential, with the Madelung shift obtained from molecular dynamics reproducing a hitherto-unexplained huge experimental shift for several battery electrode. Furthermore, incorporating the effects of entropy and polarization dynamics could polish the theoretical model to perfectly fit the experimental data. Thus, a long-awaited method for the description of the electrode potential in any electrochemical system is now available after 100 years of classical Debye-Hückel theory. [1] P. Debye & E. Hückel, Physikalische Zeitschrift, 24, 185 (1923), [2] N. Takanaka, et al., and A. Yamada, Denki Kagaku, 91, 140 (2023) [3] S.Ko, et al., and A. Yamada, Next Energy, 100014 (2023), [4] S. Ko, et al.,and A. Yamada, Nature Sustain., 6, 1705 (2023), [5] N. Takenaka, et al., and A.Yamada, Nature Comm., 15, 1319 (2024)