Masaki Hasegawa

Positive electrode for non-aqueous electrolyte lithium secondary battery and method of manufacturing the same

A positive electrode for a non-aqueous electrolyte lithium secondary battery comprises an active material represented by the formula Lix A1-y My O2 (wherein A represents at least one transition element selected from the group consisting of Mn, Co, and Ni, M represents at least one element selected from the group consisting of B, Mg, Ca, Sr, Ba, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Al, In, Nb, Mo, W, Y, and Rh, and wherein 0.05≦x≦1.1, and 0≦y≦0.5), a binder, a conductive agent and a current collector. The binder is selected from the group consisting of a copolymer comprising a tetrafluoroethylene unit and a hexafluoropropylene unit, a copolymer comprising a vinylidene fluoride unit, a copolymer comprising a propylene unit and a tetrafluoroethylene unit, and a polymer comprising a trifluoropropylmethylsiloxane unit.

Study on CxN and CxS with disordered carbon structure as the anode materials for secondary lithium batteries

Abstract C x N ( x = 12.5 and 7.3) and C x S ( x = 31.8 and 28.0) with disordered carbon structure was synthesized by chemical vapor deposition (CVD) from pyridine and thiophene, respectively, at 800 °C in the absence or presence of chlorine. Lithium was reversibly inserted into these materials. In addition, C x N and C x S had larger capacities than pyrolytic carbon synthesized by CVD from benzene at 800 °C. The capacities of C x N and C x S increased with increase in nitrogen or sulfur content. In particular, C 7.3 N had a first cycle discharge capacity of 507 mAh/g in the potential range of 0–3 V versus Li/Li + , which exceeds the theoretical capacity of graphite (372 mAh/g). C 28.0 S had a large first cycle discharge capacity of 551 mAh/g. The average interlayer spacing of C 7.3 N increased during charging and decreased during discharging like that of pyrolytic carbon. On the other hand, the average interlayer spacing of C 28.0 S hardly changed during charging and discharging.

Non-aqueous electrolyte secondary battery and method for producing anode therefor

A non-aqueous electrolyte secondary battery is disclosed which has an anode comprising a carbon material. The carbon material contains at least one of 7-35 wt % sulfur, 6.5-25 wt % oxygen and 10.5-18.3 wt % nitrogen, provided that if the carbon material contains at least two of these elements, the total amount of the elements does not exceed 35 wt %.