Electrode material for secondary battery and secondary battery

[0055]Preparation of Electrode Material

[0056]Sn-containing precursor, Mn-containing precursor, and Ni-containing precursor powders were respectively grinded using a 2D ball mill, and the Sn-containing precursor, Mn-containing precursor, and Ni-containing precursor powders were mixed and pressurized into green pellets (diameter of 1 cm). The green pellet was heated in a high-temperature furnace. The heating rate was 5° C. / minute, and the temperature was kept at 100° C. for 2 hours to evaporate moisture. Next, the temperature was increased to 1000° C. or higher and maintained for 10 hours or more and then cooled to room temperature. The sintered Sn—Mn—Ni-oxide block was broken and the powder was grinded.

[0057]Preparation of Half Battery

[0058]A Sn—Mn—Ni-oxide, conductive carbon (Super P), and polymer binder (poly(vinylidene fluoride) (PVDF)) were dissolved in a N-methylpyrrolidone (NMP) solvent and mixed at a weight ratio of 7:2:1. Five zirconia balls (diameter of 3 mm) and 0.2 g of zir