NOVELTY - High capacity and high-power secondary lithium battery has a positive electrode, an electrolyte and a negative electrode. The electrolyte contains lithium bis(fluorosulfonyl)imide, the positive electrode contains lithium-manganese oxide (I) as positive electrode material, and negative electrode contains titanium oxide or molybdenum dioxide.    USE - High capacity and high-power secondary lithium-ion battery is used for electric vehicle.    ADVANTAGE - The secondary lithium-ion battery has high power and capacity.    DETAILED DESCRIPTION - High capacity and high-power secondary lithium battery has a positive electrode, an electrolyte and a negative electrode. The electrolyte contains lithium bis(fluorosulfonyl)imide, the positive electrode contains lithium-manganese oxide of formula: bLi2MnO3.(1-b)LiMO2 (I) as positive electrode material, and negative electrode contains titanium oxide (H2Ti12O25) or molybdenum dioxide, where b is 0-1, LiMo2 is lithium-cobalt-nickel-manganese oxide (LiCoxNiyMnzO2) or lithium-manganese oxide (LiMn2O4, Li4Mn5O9 and/or Li4Mn5O12), and sum of x, y and z is 1. An INDEPENDENT CLAIM is included for preparation of secondary lithium battery, which involves preparing negative electrode sheet by dissolving active material (75-99%) of negative electrode material, conducting agent (0.5-15%) and adhesive (1-10%) in solvent for forming negative electrode, using copper foil having diameter of 9-25 mu m as collector, coating negative electrode material on copper foil, drying, rolling and cutting, preparing positive electrode sheet by dissolving active material (59-98%) of positive electrode material, conducting agent (1-40%) and adhesive (1-10%) in solvent for forming positive electrode, using copper foil having diameter of 15-40 mu m as collector, coating positive electrode material on copper foil, drying, rolling and cutting, and laminating, rolling, coating or encapsulating negative electrode, positive electrode and membrane, welding, injecting electrolyte and packaging to obtain semi-product of lithium battery, where negative electrode and positive electrode are isolated by membrane, pressurizing, capacity grading and detecting.