Toyota Jidosha Kabushiki Kaisha

Ryosuke Ohsawa

Kaoru Inoue

Akira Tsujiko

Akihiro Taniguchi

Keisuke Ohara

Koji Abe

Kei Shimamoto

Naoto Onodera

Kenta Ishii

Makoto Babazono

Provided is a positive electrode material that allows reducing the low-temperature resistance of a secondary battery. The positive electrode material of a secondary battery includes positive electrode active material particles each having a void in the interior, and a compound (A) that is present at least within the void. The average diameter of the void is not less than 0.01 &#x3bc;m and not more than 1 &#x3bc;m. The compound (A) is a nitrile group-containing polymer, and the proportion of nitrogen atoms, relative to metal atoms included in the positive electrode active material particles, other than lithium, is not less than 1 atom % and not more than 10 atom %; alternatively, the compound (A) is an alkoxysilane compound, and then the proportion of silicon atoms, relative to metal atoms included in the positive electrode active material particles, other than lithium, is not less than 1 atom % and not more than 10 atom %.

Positive electrode material of secondary battery, and secondary battery

A negative electrode for a non-aqueous electrolyte secondary battery is provided. The negative electrode includes at least a negative electrode active material. The negative electrode active material includes a first type of silicon oxide particles and a second type of silicon oxide particles. The first type of silicon oxide particles has not been pre-doped with lithium. The second type of silicon oxide particles has been pre-doped with lithium. The first type of silicon oxide particles has a first average particle size. The second type of silicon oxide particles has a second average particle size. The ratio of the second average particle size to the first average particle size is not lower than 1.5 and not higher than 11.2.

Negative electrode, non-aqueous electrolyte secondary battery, and method of producing negative electrode

A negative electrode material contains composite particles. Each of the composite particles contains a negative electrode active material particle and a film. The negative electrode active material particle contains a silicon oxide phase and a lithium silicate phase. The film covers a surface of the negative electrode active material particle. The film contains an anion-exchange resin. To an ion-exchange group of the anion-exchange resin, a fluoride ion is bound. The content of the anion-exchange resin in the negative electrode material is not higher than 33 mass %.

Negative electrode material, non-aqueous electrolyte secondary battery, and method of producing the same

A first silicon oxide material and a second silicon oxide material are prepared. A dispersion is prepared by dispersing the first silicon oxide material in an aqueous carboxymethylcellulose solution. A negative electrode composite material slurry is prepared by dispersing the second silicon oxide material and a binder in the dispersion. A negative electrode is produced by applying the negative electrode composite material slurry to a surface of a negative electrode current collector and then performing drying. The binder includes no carboxymethylcellulose. The first silicon oxide material has not been pre-doped with lithium. The second silicon oxide material has been pre-doped with lithium.

Method of producing negative electrode, negative electrode, and non-aqueous electrolyte secondary battery

A lithium-ion secondary battery includes at least a negative electrode, a positive electrode, and an electrolyte solution. The negative electrode includes at least negative electrode active material particles. Each of the negative electrode active material particles contains at least a SiOparticle and a Si layer. The Si layer covers a surface of the SiOparticle. The Si layer has a thickness not smaller than 10 nm and not greater than 100 nm. The electrolyte solution contains at least one selected from the group consisting of FEC and VC.

Lithium-ion secondary battery and method of producing the same

A lithium-ion secondary battery includes at least a negative electrode, a positive electrode, and an electrolyte. The negative electrode includes at least a negative electrode active material and a polymer binder. The negative electrode active material includes at least a graphitic material and a silicon oxide material. The amount of acidic functional groups per unit surface area of graphitic material is not lower than 0.017 mmol/mand not higher than 0.086 mmol/m. A polymer binder contains a carboxy group. Polymer binder has a main chain with a length not smaller than 0.53 &#x3bc;m and not greater than 2.13 &#x3bc;m.

A non-aqueous electrolyte secondary battery includes at least a negative electrode composite material layer. The negative electrode composite material layer includes a negative electrode active material, a conductive material, and a binder. The negative electrode active material includes a silicon oxide material and a graphite material. The negative electrode composite material layer has a BET specific surface area not smaller than 3.5 m/g and not greater than 5.0 m/g. In an orthogonal coordinate system having an abscissa representing the elongation of the negative electrode composite material layer and an ordinate representing the electrical resistance of the negative electrode composite material layer, an elongation at a bending point (Cp) in the plot is 12% or higher.

Non-aqueous electrolyte secondary battery, method of evaluating negative electrode composite material layer, and method of producing non-aqueous electrolyte secondary battery

The positive electrode includes a positive electrode composite layer. The negative electrode includes a negative electrode composite material layer. A whole of the positive electrode composite layer and a portion of the negative electrode composite material layer face each other with the separator being interposed therebetween. The negative electrode composite material layer includes a first region and a second region. The first region is a region that does not face the positive electrode composite layer and that extends from a position facing one end portion of the positive electrode composite layer to a point separated from the position by more than or equal to 0.1 mm and less than or equal to 10 mm. The second region is a region other than the first region. The first region includes silicon oxide doped with lithium. The second region includes silicon oxide.

Lithium ion secondary battery and method for manufacturing lithium ion secondary battery

A negative electrode active material, a first carbon material, a thickener, and a solvent are mixed to prepare a first dispersion solution. The first dispersion solution and a second carbon material are mixed to prepare a second dispersion solution. The second dispersion solution and a binder are mixed to prepare a negative electrode paint. The negative electrode paint is applied to a surface of a negative electrode current collector and dried to produce a negative electrode for a nonaqueous electrolyte secondary battery. The negative electrode active material has a BET specific surface area of 3 m/g or more and 8 m/g or less. The first carbon material has a BET specific surface area of 30 m/g or more and 100 m/g or less. The second carbon material has a BET specific surface area of 200 m/g or more and 500 m/g or less.

Method of producing negative electrode for nonaqueous electrolyte secondary battery and method of producing nonaqueous electrolyte secondary battery

A non-aqueous electrolyte secondary battery includes a negative electrode, a positive electrode, and an electrolyte solution. The electrolyte solution contains at least one selected from the group consisting of ethylene carbonate, fluoroethylene carbonate, and vinylene carbonate. The negative electrode includes a negative electrode mixture layer. The negative electrode mixture layer contains a silicon-containing particle and a graphite particle. In a Log-differential pore volume distribution of the negative electrode mixture layer, the ratio of a Log-differential pore volume at a pore diameter of 2 &#x3bc;m to a Log-differential pore volume at a pore diameter of 0.2 &#x3bc;m is within a range of 10.5 to 33.1.

Non-aqueous electrolyte secondary battery and method of producing the same

The negative electrode plate includes at least a negative electrode composite material layer. The negative electrode composite material layer has a density of 1.5 g/cmor more. The negative electrode composite material layer contains at least first particles, second particles and a binder. The first particles contain graphite particles and an amorphous carbon material. The amorphous carbon material is coated on the surface of each graphite particle. The second particles are made of silicon oxide. The ratio of the second particles to the total amount of the first particles and the second particles is 2 mass % or more to 10 mass % or less. The negative electrode plate has a spring constant of 700 kN/mm or more to 3000 kN/mm or less.

Negative electrode plate and non-aqueous electrolyte secondary battery

The present teaching provides a non-aqueous electrolyte secondary battery provided with a non-aqueous electrolyte solution having a composition able to achieve high battery performance even in an extremely low temperature region (for example, &#x2212;30&#xb0; C. or lower). The non-aqueous electrolyte solution disclosed herein contains, as non-aqueous solvents, ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), ethyl methyl carbonate (EMC) and ethyl propionate (EP), and when the total volume of the non-aqueous solvents is 100 vol. %, the content of EC is 20 to 30 vol. %, the content of PC is 5 to 10 vol. %, the content of EP is 5 to 10 vol. %, and the content of DMC+EMC is 50 to 70 vol. %.

Non-aqueous electrolyte secondary battery

A negative electrode active material particle has a composition represented by the following formula (I): SiOD. . . (I). In the formula (I), x satisfies 0&#x2264;x&#x2264;1.5. D is a group 13 element or a group 15 element in a periodic table. In an outermost surface of the negative electrode active material particle, y satisfies 10&#x2264;y&#x2264;10. In a center of the negative electrode active material particle, y satisfies y&#x2264;10.

Negative electrode active material particle, negative electrode, lithium ion secondary battery, and method of producing negative electrode active material particle

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Okazaki, Japan

Ryosuke Ohsawa