A lead-acid battery includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The negative electrode plate includes a negative electrode material. The negative electrode material contains a polymer compound, and the polymer compound has a peak in a range of 3.2 ppm or more and 3.8 ppm or less in a chemical shift of .sup.1H-NMR spectrum. Alternatively, the negative electrode material contains a polymer compound having a repeating structure of oxy C.sub.2-4 alkylene units. A ratio: C.sub.n/S.sub.n of a content C.sub.n of the polymer compound in the negative electrode material to a specific surface area S.sub.n of the negative electrode material is 25 ppm.Math.m.sup.−2.Math.g or more.

A lead-acid battery includes a positive electrode plate, a negative electrode plate, and an electrolyte solution. The negative electrode plate includes a negative electrode material. The negative electrode material contains a polymer compound. The polymer compound has a peak in a range of 3.2 ppm or more and 3.8 ppm or less in a chemical shift of .sup.1H-NMR spectrum, or the negative electrode material contains a polymer compound having a repeating structure of oxy C.sub.2-4 alkylene units.

A lead-acid battery provided with a negative electrode plate, a positive electrode plate, and an electrolyte solution. The negative electrode plate includes a negative current collector and a negative electrode material. When it is defined in a log differential pore volume distribution of the negative electrode material that a) a region having a pore size of 1 to 3 μm is a P region, b) a region having a pore size of 6 to 15 μm is a Q region, c) a maximum value of the log differential pore volume in the P region is P, and d) a maximum value of the log differential pore volume in the Q region is Q, after initial degradation, during use, or after 1220 cycles in a light-load life test in which charge and discharge of constant current discharge at 25 A for one minute and constant voltage charge at 2.47 V/cell and an upper limit current of 25 A for ten minutes are repeated at a test temperature of 75° C., the log differential pore volume distribution of the negative electrode material has a peak p corresponding to the maximum value P in the P region and a peak q corresponding to the maximum value Q in the Q region, and the maximum value P and the maximum value Q satisfy 0.25≤P/(P+Q)≤0.63.

A secondary battery has a battery body and a restraint. The battery body has a plurality of stacked power generation elements. The restraint restrains the battery body. The restraint has a first contact section (for applying a restraining force to an outermost layer surface (e.g., a negative electrode collector) of the battery body. The restraint is configured so that a stress occurring at a boundary of a non-contact region and a contact region of the first contact section is less than a breaking strength of the negative electrode collector, and the stress is based on the restraining force and on expansion and contraction of a negative electrode due to a change in volume of a negative electrode active material layer caused by charging and discharging.

A slurry is prepared by mixing active material particles, capsule-shaped particles, a binder, and an organic solvent. The slurry is applied to a surface of a substrate to form a coating film. The coating film is heated to dry to form an active material layer. The active material layer is compressed to produce an electrode. Each of the capsule-shaped particles includes a thermoplastic resin. The thermoplastic resin softens when heated in the presence of the organic solvent. When the thermoplastic resin softens, the capsule-shaped particles shrink to form voids in the active material layer.

A secondary battery has a battery body and a restraint. The battery body has a plurality of stacked power generation elements. The restraint restrains the battery body. The restraint has a first contact section (for applying a restraining force to an outermost layer surface (e.g., a negative electrode collector) of the battery body. The restraint is configured so that a stress occurring at a boundary of a non-contact region and a contact region of the first contact section is less than a breaking strength of the negative electrode collector, and the stress is based on the restraining force and on expansion and contraction of a negative electrode due to a change in volume of a negative electrode active material layer caused by charging and discharging.

A composition suitable for a negative plate of lead-acid battery includes (a) a lead-based active material; (b) at least one material selected from the group consisting of a lignosulfonate and barium sulfate; and (c1) carbon black particles having a Brunauer-Emmett-Teller (BET) surface area greater than or equal to 90 m.sup.2/g and less than or equal to 900 m.sup.2/g, and an oil adsorption number (OAN) greater than or equal to 150 mL/100 g and less than or equal to 300 mL/100 g, or (c2) carbon black particles having a BET surface area greater than or equal to 40 m.sup.2/g and less than or equal to 500 m.sup.2/g, and graphenes particles. The composition has a theoretical negative active mass (NAM) BET surface area greater than or equal to 0.75 m.sup.2/g and less than or equal to 2 m.sup.2/g. The compositions can be used in electrodes, e.g., those used in lead-acid batteries.

Various graphite additives were incorporated into the positive battery paste composition to compare their effects on the positive active mass utilization of lead-acid batteries. The disclosure is related to battery paste composition for preparing a lead-acid battery plate comprising a graphite additive selected from the group consisting of globular natural graphite, natural flake graphite, expanded flake graphite, and combinations thereof. The disclosure is also related to a battery paste composition comprising a sodium polymethacrylate dispersant. The disclosure is further related to batteries prepared by these battery paste compositions.

A carbon-based additive for negative active materials includes carbon nanostructures free of a fiber substrate, carbon nanostructures fused to a fiber substrate or any combination thereof. In many cases, the carbon-based additive further includes carbon black. The additive is used to prepare electrode compositions for lead acid batteries. Batteries that include such electrode compositions are characterized by improved dynamic charge acceptance and lead utilization, typically at acceptable water loss levels. Some of the batteries described herein exhibit a negligible memory effect.

Described herein is a positive electrode comprising an active material particle, an acetylene black particle and net-like graphene. The positive electrode can be used in a battery.