Considering　the　coupling　effect　between　diffusion　and　stress　on　diffusion-induced　stress　presented　in　a　lithium-ion　battery,　the　finite　element　method　is　used　to　analyze　the　diffusion-induced　interfacial　delamination　of　a　thin　film　from　a　deformable　substrate　under　a　potentiostatic　condition.　Both　the　film　and　the　substrate　are　elastic-perfectly　plastic,　and　solute　atoms　diffuse　into　the　thin　film　only　from　top　and　side　surfaces　of　the　thin　film.　A　linear　traction-separation　law　is　used　to　describe　the　bonding　between　the　film　and　the　substrate.　Numerical　results　show　that　both　the　radial　stress　and　the　hoop　stress　in　the　material　near　the　top　surface　of　the　thin　film　are　at　a　tensile　state　during　lithiation,　which　can　lead　to　interface　damage/delamination　and　surface　cracking　concurrently.　A　film-substrate　structure　consisting　of　a　substrate　with　small　elastic　modulus　and　yield　stress　and　a　thin　film　of　a　small　film　thickness　is　desirable　to　inhibit　interface　damage　and　delamination.　©　2017　IOP　Publishing　Ltd.