Transportation　sector　is　one　of　the　major　sources　of　pollutants　as　it　contributes　more　than　80%　of　CO,　while　almost　all　HC　and　90%　of　NOx　and　PM.　Although　battery　electric　vehicles　are　well-known　for　reducing　environmental　pollution,　the　driving　range　and　battery　lifespan　put　a　significant　barrier　to　its　large-scale　commercialization.　In　this　study,　an　integrated　system,　which　includes　an　uninterrupted　dual　input　transmission　and　hybrid　energy　storage　system,　is　proposed　to　improve　energy　efficiency　and　extend　battery　lifespan.　Given　the　limitations　of　dynamic　programming　in　practice,　a　real-time　optimal　control　strategy　is　designed　to　evaluate　the　power　loss　and　battery　capacity　degradation　of　the　proposed　integrated　system　based　on　detailed　mathematical　models　of　individual　powertrain　components.　To　achieve　a　desirable　trade-off　between　battery　degradation,　energy　consumption,　and　acquisition　cost,　a　mixed-integer　multi-objective　genetic　algorithm　is　implemented　to　optimize　the　parameters　of　the　hybrid　energy　storage　system,　while　Pareto　principal　is　adopted　to　find　the　proper　solution　according　to　different　purposes.　The　simulation　results　reveal　that　the　proposed　integrated　system　shows　the　potential　of　saving　15.85%-20.82%　of　the　energy　consumption　in　typical　driving　cycles　and　more　than　22.61%-31.11%　Life-cycle　cost　compared　with　the　single-ratio　transmission-based　battery　electric　vehicles.　The　selected　Pareto　front　can　further　enhance　Life-cycle　cost　from　26.53%　to　28.13%　in　the　HWFET　cycle.　It　can　be　concluded　that　the　integrated　uninterrupted　dual　input　transmission　and　hybrid　energy　storage　system　not　only　can　improve　motor　efficiency　and　reduce　energy　consumption,　it　also　can　extend　the　battery　lifespan　to　decrease　Life-cycle　cost　compared　to　conventional　single-ratio　battery-only　EV.