Cathodes　of　lithium-rich　layered　oxides　for　high-energy　Li-ion　batteries　in　electrically　powered　vehicles　are　attracting　considerable　attention　by　the　research　community.　However,　current　research　is　insufficient　to　account　for　their　complex　reaction　mechanism　and　application.　Here,　the　structural　evolution　of　lithium-manganese-rich　layered　oxides　at　different　temperatures　during　electrochemical　cycling　has　been　investigated　thoroughly,　and　their　structural　stability　has　been　designed.　The　results　indicated　structure　conversion　from　the　two　structures　into　a　core-shell　structure　with　a　single　distorted-monoclinic　LiTMO2　structure　core　and　disordered-spinel/rock　salt　structure　shell,　along　with　lattice　oxygen　extraction　and　lattice　densification,　transition-　metal　migration,　and　aggregation　on　the　crystal　surface.　The　structural　conversion　behavior　was　found　to　be　seriously　temperature　sensitive,　accelerated　with　higher　temperature,　and　can　be　effectively　adjusted　by　structural　design.　This　study　clarifies　the　structural　evolution　mechanism　of　these　lithium-rich　layered　oxides　and　opens　the　door　to　the　design　of　similar　high-energy　materials　with　better　cycle　stability.