Systems and methods for water soluble weak acidic resins as carbon precursors for silicon-dominant anodes may include an electrode coating layer on a current collector, where the electrode coating layer is formed from silicon and pyrolyzed water-soluble acidic polyamide imide as a primary resin carbon precursor. The electrode coating layer may include a pyrolyzed water-based acidic polymer solution additive. The polymer solution additive may include one or more of: polyacrylic acid (PAA) solution, poly (maleic acid, methyl methacrylate/methacrylic acid, butadiene/maleic acid) solutions, and water soluble polyacrylic acid. The electrode coating layer may include conductive additives. The current collector may include a metal foil, where the metal current collector includes one or more of a copper, tungsten, stainless steel, and nickel foil in electrical contact with the electrode coating layer. The electrode coating layer may be more than 70% silicon.

Systems and methods for water soluble weak acidic resins as carbon precursors for silicon-dominant anodes may include an electrode coating layer on a current collector, where the electrode coating layer is formed from silicon and pyrolyzed water-soluble acidic polyamide imide as a primary resin carbon precursor. The electrode coating layer may include a pyrolyzed water-based acidic polymer solution additive. The polymer solution additive may include one or more of: polyacrylic acid (PAA) solution, poly (maleic acid, methyl methacrylate/methacrylic acid, butadiene/maleic acid) solutions, and water soluble polyacrylic acid. The electrode coating layer may include conductive additives. The current collector may include a metal foil, where the metal current collector includes one or more of a copper, tungsten, stainless steel, and nickel foil in electrical contact with the electrode coating layer. The electrode coating layer may be more than 70% silicon.

Provided is a binder composition for lithium ion secondary battery electrode-use that reduces internal resistance of a lithium ion secondary battery while also providing the lithium ion secondary battery with excellent life characteristics. The binder composition contains a copolymer X and a solvent. The copolymer X is obtained from a monomer composition X that contains at least 20.0 mass % and no greater than 75.0 mass % of an ethylenically unsaturated carboxylic acid compound (A) composed of either or both of an ethylenically unsaturated carboxylic acid and an ethylenically unsaturated carboxylic acid salt, and at least 20.0 mass % and no greater than 75.0 mass % of a copolymerizable compound (B) that has an ethylenically unsaturated bond and a solubility of at least 7 g in 100 g of water at 20° C. The copolymer X has a degree of swelling in electrolysis solution of less than 120 mass %.

Provided is a binder composition for lithium ion secondary battery electrode-use that reduces internal resistance of a lithium ion secondary battery while also providing the lithium ion secondary battery with excellent life characteristics. The binder composition contains a copolymer X and a solvent. The copolymer X is obtained from a monomer composition X that contains at least 20.0 mass % and no greater than 75.0 mass % of an ethylenically unsaturated carboxylic acid compound (A) composed of either or both of an ethylenically unsaturated carboxylic acid and an ethylenically unsaturated carboxylic acid salt, and at least 20.0 mass % and no greater than 75.0 mass % of a copolymerizable compound (B) that has an ethylenically unsaturated bond and a solubility of at least 7 g in 100 g of water at 20° C. The copolymer X has a degree of swelling in electrolysis solution of less than 120 mass %.

An electricity storage device includes a negative electrode having a layered structure that includes an organic backbone layer containing an aromatic compound having an aromatic ring structure, the aromatic compound being in the form of dicarboxylate anions, and an alkali metal element layer containing an alkali metal element coordinated with oxygen in the dicarboxylate anions to form a backbone, a positive electrode that provides electric double-layer capacity, and a nonaqueous electrolyte solution provided between the negative electrode and the positive electrode, the nonaqueous electrolyte solution containing an alkali metal salt. The layered structure may be provided in layers by a π-electron interaction of the aromatic compound and may have a monoclinic crystal structure belonging to the space group P2.sub.1/c. The positive electrode may contain activated carbon having a specific surface area of 1,000 m.sup.2/g or more.

An electricity storage device includes a negative electrode having a layered structure that includes an organic backbone layer containing an aromatic compound having an aromatic ring structure, the aromatic compound being in the form of dicarboxylate anions, and an alkali metal element layer containing an alkali metal element coordinated with oxygen in the dicarboxylate anions to form a backbone, a positive electrode that provides electric double-layer capacity, and a nonaqueous electrolyte solution provided between the negative electrode and the positive electrode, the nonaqueous electrolyte solution containing an alkali metal salt. The layered structure may be provided in layers by a π-electron interaction of the aromatic compound and may have a monoclinic crystal structure belonging to the space group P2.sub.1/c. The positive electrode may contain activated carbon having a specific surface area of 1,000 m.sup.2/g or more.

A negative electrode with little degradation is provided. Alternatively, a novel negative electrode is provided. A secondary battery includes a positive electrode and a negative electrode, and the negative electrode includes a solvent containing fluorine, a current collector, a negative electrode active material, and graphene. The negative electrode further includes a solid electrolyte material and the solid electrolyte material is an oxide. The negative electrode active material may contain fluorine. The secondary battery may include a plurality of electrolytes different from each other. The negative electrode active material is, for example, a material containing one or more elements selected from silicon, tin, gallium, aluminum, germanium, lead, antimony, bismuth, silver, zinc, cadmium, and indium.

The present disclosure provides porous composites for manufacture of cathodes for secondary sulfur batteries and batteries containing such cathodes.

A secondary battery, and a battery module, a battery pack, and an electric apparatus containing the same are provided. The secondary battery includes: an electrolyte having a specific percentage of a low-viscosity solvent, a specific percentage of a high-dielectric-constant solvent, and a negative electrode having a negative electrode active material layer, and the secondary battery satisfies the relational expression:

[00001]$1\times {10}^{-4}4\le \frac{B\times C\times P}{ \mathrm{OI}\times \mathrm{CW}}\le 1\times {10}^{-3}$

where B is the percentage of the low-viscosity solvent in total solvent in the electrolyte by mass; C is a percentage of an electrolyte salt in the electrolyte by mass; P is a porosity of the negative electrode active material layer; CW is a coating weight of the negative electrode active material layer, measured in mg/cm.sup.2; and OI is an orientation index of the negative electrode active material layer.

A cathode active material includes a lithium composite oxide having a crystal structure which belongs to a layered structure. The lithium composite oxide has a BET specific surface area of not less than 5 m.sup.2/g and not more than 10 m.sup.2/g. The lithium composite oxide has an average particle size of not less than 3 μm and not more than 30 μm. The lithium composite oxide, an average crystallite size calculated by an X-ray diffraction method is not less than 150 Å and not more than 350 Å.