Factors that affect volume change during electrochemical cycling in cathode materials for lithium ion batteries†
Intergranular cracks originating from volume change during charging/discharging have been observed in many cathodes of lithium ion batteries, which are considered to be closely related to capacity fading. Using first principles calculations to systematically study the volume behavior of representative intercalation cathodes during delithiation, we have elucidated how Coulombic interaction and bond length affect the volume behaviors of cathodes with different structural flexibility. Jahn–Teller distortions, dopants, ionic radii, site-exchanges, and deintercalation mechanisms have also been discussed to account for the volume change of different cathode materials. This study attempts to give an integrated picture of volume change in typical lithium intercalation cathodes and strives to provide helpful clues to the design of high-capacity-maintaining cathodes.