  Mechanical degradation in electrode materials during successive
electrochemical cycling is critical for battery lifetime and aging properties.
A common strategy to mitigate electrode mechanical degradation is to suppress
the volume variation induced by Li/Na intercalation/deintercalation, thereby
designing strain-less electrodes. In this study, we investigate the
electrochemically-induced volume variation in layered and spinel compounds used
in Li-ion and Na-ion battery electrode materials through density functional
theory computations. Specifically, we propose to decompose the volume variation
into electronic, ionic, and structural contributions. Based on this analysis,
we suggest methods to separately influence or control each contribution through
strategies such as chemical substitution, doping, and polymorphism. Altogether,
we conclude that volume variations can be controlled by designing either
mechanically hard or compact electrode materials.
