Compared　to　titanium　oxide(TiO2),　non-equilibrium　stoichiometry　titanium　oxides(TiO2-x)　are　promising　electrode　materials　because　oxygen　vacancy　changes　the　electronic　interaction　near　E-F.　However,　the　structural　configuration　of　Ti3O5　(alpha-Ti3O5　and　beta-Ti3O5)　remains　considerable　controversy.　In　particular,　the　electrochemical　performance　of　TiO2-x　is　entirely　unclear.　By　means　of　first-principles　calculations,　we　present　the　results　of　structure,　average　open　circuit　voltage　(Vac)　and　electronic　structure　of　Ti3O5　and　Ti2O3,　respectively.　We　find　that　our　predicted　Ti3O5(C2/c)　monoclinic　structure　is　more　stable　than　(1-Ti3O5　and　beta-Ti3O5　because　of　the　cohesive　force　between　layered-layered　structure.　We　demonstrate　that　alpha-Ti3O5　and　beta-Ti3O5　are　dynamically　instable　due　to　the　vibration　of　the　O　and　Ti　at　the　low　frequency　region.　Importantly,　we　firstly　predict　a　novel　Ti3O5(C2/c)　monoclinic　structure.　Compared　to　TiO2,　Ti3O5　and　Ti2O3　exhibit　metallic　behavior　because　Ti-3d　and　O-2p　bands　across　E-F.　In　particular,　the　calculated　V-oc　of　Ti3O5　(C2/c)　monoclinic　structure　(3.416　V)　is　much　larger　than　that　of　the　alpha-Ti3O5　(1.809　V),　beta-Ti3O5　(1.454　V)　and　Ti2O3　(2.255　V)　due　to　the　two　O　sub-boundary　layers.　We　believe　that　our　work　opens　a　new　opportunity　for　developing　the　titanium　oxide　as　application　of　lithium　ion　batteries.　(C)　2020　Hydrogen　Energy　Publications　LLC.　Published　by　Elsevier　Ltd.　All　rights　reserved.