Flexible　lithium-ion　batteries　(FLBs)　are　of　critical　importance　to　the　seamless　power　supply　of　flexible　and　wearable　electronic　devices.　However,　the　simultaneous　acquirements　of　mechanical　deformability　and　high　energy　density　remain　a　major　challenge　for　FLBs.　Through　billions　of　years　of　evolutions,　many　plants　and　animals　have　developed　unique　compositional　and　structural　characteristics,　which　enable　them　to　have　both　high　mechanical　deformability　and　robustness　to　cope　with　the　complex　and　stressful　environment.　Inspired　by　nature,　many　new　materials　and　designs　emerge　recently　to　achieve　mechanically　flexible　and　high　storage　capacity　of　lithium-ion　batteries　at　the　same　time.　Here,　we　summarize　these　novel　FLBs　inspired　by　natural　and　biological　materials　and　designs.　We　first　give　a　brief　introduction　to　the　fundamentals　and　challenges　of　FLBs.　Then,　we　highlight　the　latest　achievements　based　on　nature　inspiration,　including　fiber-shaped　FLBs,　origami　and　kirigami-derived　FLBs,　and　the　nature-inspired　structural　designs　in　FLBs.　Finally,　we　discuss　the　current　status,　remaining　challenges,　and　future　opportunities　for　the　development　of　FLBs.　This　concise　yet　focused　review　highlights　current　inspirations　in　FLBs　and　wishes　to　broaden　our　view　of　FLB　materials　and　designs,　which　can　be　directly　＂borrowed＂　from　nature.