Abstract:
It is an object of the present invention to provide a nonaqueous electrolyte secondary battery improved not only in room-temperature output but also in low-temperature regeneration. A positive electrode plate contains a lithium transition metal oxide as a positive electrode active material. A mix of the positive electrode plate contains a tungsten oxide and a phosphate compound. A nonaqueous electrolyte contains a linear sulfonate. When both of the tungsten oxide and the phosphate compound are present near the positive electrode active material, the linear sulfonate forms a movable decomposition product by oxidative decomposition on a surface of a positive electrode without forming any coating and the decomposition product and the unreacted linear sulfonate are reductively decomposed on a surface of the negative electrode together and a low-resistance coating is thereby formed.
Abstract:
In a nonaqueous electrolyte secondary battery containing a silicon material as a negative electrode active material, the initial charge-discharge efficiency is improved. Negative electrode active material particles (10) according to an embodiment each contain a lithium silicate phase (11) represented by Li2zSiO(2+z) (where 0
Abstract:
A nonaqueous electrolyte secondary battery which can suppress the change in structure of a positive electrode active material at a high voltage is provided. The nonaqueous electrolyte secondary battery has a positive electrode including a positive electrode active material which absorbs and releases lithium ions; a negative electrode including a negative electrode active material which absorbs and releases lithium ions; and a nonaqueous electrolyte. The positive electrode active material has a surface to which a rare earth compound is adhered and includes a lithium cobalt composite oxide containing at least one type selected from the group consisting of Ni, Mn, Ca, Cu, Zn, Sr, Ge, Sn, Si, P, Nb, Mo, S, and W, and charge is performed so that the potential of the positive electrode is 4.53 V or more with reference to lithium.
Abstract:
A lithium secondary battery which is unlikely to be deformed during charging and discharging. A lithium secondary battery includes a spiral-shaped electrode assembly and a cylindrical battery container. The battery container receives the electrode assembly. The electrode assembly includes a negative electrode, a positive electrode, and a separator. The negative electrode includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is disposed on the negative electrode collector. The negative electrode active material layer contains a negative electrode active material forming an alloy with lithium. The positive electrode faces the negative electrode. The separator is disposed between the negative electrode and the positive electrode. When A is a proof stress of the negative electrode collector multiplied by the thickness thereof and a capacity to be charged per unit area of the negative electrode is represented by B, A≧0.075×B−3 is satisfied.
Abstract:
It is an object of the present invention to provide a nonaqueous electrolyte secondary battery with improved output characteristics. An example of an embodiment of the present invention provides a nonaqueous electrolyte secondary battery comprising an electrode assembly having a structure in which a positive electrode plate and a negative electrode plate are stacked with a separator therebetween. The positive electrode plate contains a lithium transition metal oxide containing tungsten as a positive electrode active material and also contains a phosphate compound. The negative electrode plate contains a graphitic carbon material and an amorphous/noncrystalline carbon material as negative electrode active materials and includes a coating of tungsten or a tungsten compound on the surface of the amorphous/noncrystalline carbon material.
Abstract:
It is an object of the present invention to provide a nonaqueous electrolyte secondary battery with improved output characteristics. An example of an embodiment of the present invention provides a nonaqueous electrolyte secondary battery comprising an electrode assembly having a structure in which a positive electrode plate and a negative electrode plate are stacked with a separator therebetween. The positive electrode plate contains a lithium transition metal oxide containing tungsten as a positive electrode active material and also contains a phosphate compound. The negative electrode plate contains a graphitic carbon material and an amorphous/noncrystalline carbon material as negative electrode active materials and includes a coating of tungsten or a tungsten compound on the surface of the amorphous/noncrystalline carbon material.
Abstract:
It is an object of the present invention to improve the low-temperature output characteristics of a nonaqueous electrolyte secondary battery. A nonaqueous electrolyte secondary battery according to an embodiment includes an electrode assembly having a structure in which a positive electrode and a negative electrode are stacked with a porous separator provided therebetween. The positive electrode contains tungsten and a phosphate compound. The separator contains a material having higher oxidation resistance than a polyethylene and has a pore distribution peak sharpness index of 40 or more in the range of 0.01 μm to 10 μm as calculated using formula 1: formula 1: pore distribution peak sharpness index=(peak value of Log differential pore volume)/(difference between maximum pore size and minimum pore size at position corresponding to ½ peak value of Log differential pore volume).
Abstract:
A nonaqueous electrolyte secondary battery which can suppress the change in structure of a positive electrode active material at a high voltage is provided. The nonaqueous electrolyte secondary battery has a positive electrode including a positive electrode active material which absorbs and releases lithium ions; a negative electrode including a negative electrode active material which absorbs and releases lithium ions; and a nonaqueous electrolyte. The positive electrode active material has a surface to which a rare earth compound is adhered and includes a lithium cobalt composite oxide containing at least one type selected from the group consisting of Ni, Mn, Ca, Cu, Zn, Sr, Ge, Sn, Si, P, Nb, Mo, S, and W, and charge is performed so that the potential of the positive electrode is 4.53 V or more with reference to lithium.
Abstract:
A non-aqueous electrolyte secondary battery positive electrode capable of suppressing a decomposition reaction of an electrolyte solution in an overcharged state is provided. A non-aqueous electrolyte secondary battery positive electrode according to this embodiment includes a positive electrode active material layer which includes a positive electrode active material (54) containing a lithium transition metal oxide, a tungsten compound (56), a phosphoric acid compound (58) not in contact with the positive electrode active material (54), and an electrically conductive agent (52) in contact with the tungsten compound (56) and the phosphoric acid compound (58).
Abstract:
Provided is a negative electrode active material, containing at least silicon, for nonaqueous electrolyte secondary batteries. Since the negative electrode active material contains silicon, the negative electrode active material has high capacity and excellent cycle characteristics. A negative electrode active material for nonaqueous electrolyte secondary batteries contains at least silicon. At least, one portion of the surface of each of primary particles containing silicon is covered with an inert phase made of a silicon compound with a silicon oxidation number higher than that of the silicon, a metal-silicon alloy, or metal. The primary particles containing silicon may form secondary particles. The silicon compound with a silicon oxidation number higher than that of silicon is preferably Li2Si2O5, Li2SiO3, or Li4SiO4. Furthermore, the metal-silicon alloy is preferably FeSi and the metal is preferably Ti. Furthermore, the crystallite size of silicon is 500 Å or less.