TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The first lithium salt comprises lithium difluoro(oxalato) borate) and/or lithium bis(oxalato) borate. The second lithium salt excluding boron comprises lithium hexafluorophosphate, lithium hexafluoroantimonate, lithium hexafluoroarsenate, lithium perchlorate, lithium trifluoromethane sulfonate, lithium nonafluorobutane sulfonate, lithium bis(trifluoromethanesulfonyl) imide, lithium bis(trifluoroethanesulfonyl) imide, lithium aluminate, lithium tetrachloroaluminate, lithium imide of formula (LiN(CpF2p+1SO2)(CqF2q+1SO2)) (where p and q are natural numbers), lithium trifluoromethanesulfonate, lithium chloride and/or lithium iodide. The first lithium salt and the second lithium salt are included in a mole ratio of 0.01:1.7-1:0.5, preferably 0.4 to 1:1. The material capable of alloying with lithium comprises sodium, potassium, rubidium, cesium, francium, beryllium, magnesium, calcium, strontium, barium, radium, titanium, silver, zinc, cadmium, aluminum, gallium, indium, silicon, germanium, tin, lead, antimony and/or bismuth. The material comprises transition metal oxide, and a material capable of doping and dedoping lithium comprises silicon, silicon oxide of formula (SiOx) (where x is 0-2), tin, tin dioxide, tin alloy composites and/or silicon alloy composites (all preferred) or vanadium oxide and/or lithium vanadium oxide. Preferred Definitions:    R1-R4 = alkylene oxide, and at least one non-adjacent -CH2- in the alkylene oxide is/are replaced with -CO-, and at least two R1-R4 are fused to form a ring.    EXAMPLE - Negative active material of silicon oxide, polyvinylidene fluoride and conductive material Super P (RTM: Conductive carbon blacks) were mixed in a ratio of 90:8:2 in N-methylpyrrolidone to get negative electrode slurry. Then the negative electrode slurry was coated on a copper foil to get a thin electrode plate. The thin electrode plate was dried at 135 degrees C for 3 hours, and pressed to get a negative electrode plate (45 mu m thickness). The obtained negative electrode was used for a working electrode, a metal lithium foil was used for a counter electrode, and a separator composed of a porous polypropylene film was interposed between the working electrode and the counter electrode. Lithium hexafluorophosphate and lithium bis(oxalato) borate at a mole ratio of 7:3 were dissolved in mixed solvent of propylene carbonate, diethyl carbonate and ethylene carbonate (1:1:1) into a concentration of 1M to obtain a electrolyte solution, which then forms a 2016 coin type half cell.