Provided is a positive electrode for a secondary battery that can cause a secondary battery to display excellent battery characteristics. The positive electrode for a secondary battery includes a positive electrode mixed material layer and a current collector. The positive electrode mixed material layer contains a positive electrode active material, a conductive material, a polymer A including a nitrogen-containing heterocycle and having a weight-average molecular weight of not less than 300 and not more than 70,000, and a polymer B including a nitrile group. The positive electrode mixed material layer has a degree of nitrogen segregation of 1.4 or less as determined using an electron probe microanalyzer.

A method for producing superabsorbent polymers from polyacrylonitrile (PAN) virgin or recycled from acrylic fibre manufacturing waste and discarded fabrics subjecting the PAN to alkaline hydrolysis with pressurized water vapour of up to 5 kgf/cm.sup.2 and a PAN:OH.sup.− molar ratio of 1:0.5 to 0.95, to obtain a cross-linked poly(acrylic acid-co-acrylamide) salt without using mechanical agitation, graphitizing agents with starch or cross-linking agents, and without precipitating the superabsorbent polymer obtained from the reaction medium with solvents or through pH adjustment with acids, the polymer obtained with recycled PAN leaves the autoclave already having a moisture content of 20% to 35% and a swelling capacity of >150 g H.sub.2O/g.

Described herein are borate salts useful as additives, binders, and electrolyte salts for solid state lithium ion batteries. In particular, the borate salts of Formula (I), Formula (II) and Formula (III) as described herein: ##STR00001##
can be polymerized, or can be bound to an existing polymer, to provide polymeric binders for ceramic solid state electrolytes that are themselves capable of ion transport independent of the ceramic.

A binder for preparing a positive electrode of a lithium secondary battery, and a method for preparing a positive electrode using the same. The binder includes two or more different lithium-substituted polyacrylic acids with different molecular weights. The lithium-substituted polyacrylic acids include two different lithium-substituted polyacrylic acids differing in weight average molecular weight by 500,000 or more from each other.

A binder for preparing a positive electrode of a lithium secondary battery, and a method for preparing a positive electrode using the same. The binder includes two or more different lithium-substituted polyacrylic acids with different molecular weights. The lithium-substituted polyacrylic acids include two different lithium-substituted polyacrylic acids differing in weight average molecular weight by 500,000 or more from each other.

An electrochemical apparatus includes a positive electrode plate. The positive electrode plate includes a positive electrode material layer. The positive electrode material layer includes a fluorine-containing polymer and a cyano-containing polymer. A ratio b/a of a mole number b of nitrogen to a mole number a of fluorine in the positive electrode material layer satisfies 0.1≤b/a≤0.5. Adding the fluorine-containing polymer and the cyano-containing polymer in the positive electrode material layer and controlling the ratio b/a satisfies the above relationship enable a good bonding effect between particles in the positive electrode material layer. In addition, after cyano functional groups interact with transition metal ions of the positive electrode active material at full charge, oxidizing ability of transition metal ions is weakened, reducing side reactions between the positive electrode material layer and electrolyte, thereby improving high-temperature performance of the electrochemical apparatus.

Provided is a binder for a battery, including a fluorine-containing copolymer, wherein the fluorine-containing copolymer comprises a repeating unit (a) based on vinylidene fluoride and at least one repeating unit (b) selected from the group consisting of a repeating unit (bl) represented by a specific structural formula (bl) and a repeating unit (b2) represented by a structural formula (b2), and the fluorine-containing copolymer has a molar ratio of the repeating unit (a) to the repeating unit (b), (a)/(b), of 95/5 to 5/95.

The present invention relates to an electrode for a secondary battery including an electrode current collector, an electrode active material combination layer formed on one or both sides of the electrode current collector, and a polyurethane-based coating layer formed on the electrode active material combination layer, and a lithium secondary battery including the same.

A composite binder composition for an all-solid-state battery includes: a first polymer comprising a repeating structure represented by Chemical Formula 1a or Chemical Formula 1b below, and a second polymer comprising at least one selected from a group consisting of diene-based rubber, polysiloxane, and combinations thereof:

##STR00001##

A composite active material particle that can reduce battery resistance when used in an all-solid-state lithium ion battery is disclosed. The composite active material particle comprises: an active material particle; and a lithium ion conducting oxide with which at least part of a surface of the active material particle is coated, wherein the moisture content in the composite active material particle is no more than 319 ppm.