This application discloses a negative-electrode active material and a preparation method thereof, a secondary battery, and a battery module, a battery pack, and an apparatus that include such secondary battery. The negative-electrode active material includes a core and a coating layer covering at least part of a surface of the core, where the core includes artificial graphite, the coating layer includes amorphous carbon, a volume-based particle size distribution of the negative-electrode active material satisfies D.sub.v99≤24 μm, a volume-based median particle size D.sub.v50 of the negative-electrode active material satisfies 8 μm≤D.sub.v≤15 μm, D.sub.v99 is a particle size corresponding to a cumulative volume distribution percentage of the negative-electrode active material reaching 99%, and WO is a particle size corresponding to a cumulative volume distribution percentage of the negative-electrode active material reaching 50%.

Disclosed are an anode-free all-solid-state battery which may operate at low temperature conditions, such as room temperature, and a method manufacturing the same. The anode-free all-solid-state battery may have uniformly deposited lithium during charging and inhibit the growth of lithium dendrites.

The present disclosure describes energy storage (e.g., electrochemical) devices with customized architectures. Such customized architectures include multilayered electrode films and/or multidimensional electrode films.

A negative electrode includes at least a negative electrode composite material layer. The negative electrode composite material layer contains at least composite particles and a binder. Each composite particle includes a negative electrode active material particle and a film. The film covers at least part of a surface of the negative electrode active material particle. The film contains a layered silicate mineral. The binder includes nanofibers.

Provided are a paste for a secondary battery, and method of producing the same, with which it is possible to produce an electrode that can reduce internal resistance of a secondary battery and that can cause the secondary battery to display excellent cycle characteristics. The paste for a secondary battery contains a conductive additive, a polymer, and a dispersion medium. The conductive additive includes one or more carbon nanotubes having a surface base content of not less than 0.01 mmol/g and not more than 0.10 mmol/g and a ratio of surface acid content relative to the surface base content of not less than 0.1 and not more than 1.0.

A lithium ion battery current collector which is used in a lithium ion battery in contact with an electrode active material at one principal surface, characterized in that the current collector is provided with a surface layer on the principal surface in contact with the electrode active material, and an uneven structure is provided on a surface in which the surface layer is in contact with the electrode active material, the uneven structure is any of a plurality of recesses composed of closed figures as seen from above, a network structure, or a pattern of recesses and protrusions, which is provided in an outermost layer of the surface layer, and a depth of the recess is 10 to 45 μm, a length of a shortest portion of lengths passing through a centroid of the recess is 30 to 105 μm, and a proportion of an area of the recess as seen from above is 19% to 61% with respect to an area of a surface of the current collector provided with the recess as seen from above.

A method for manufacturing a negative electrode, including the steps of preparing a negative electrode slurry including low-expansion natural graphite, a binder polymer, a conductive material and a dispersion medium; applying the negative electrode slurry to at least one surface of a negative electrode current collector, drying the coated negative electrode slurry, to form a preliminary negative electrode having a preliminary negative electrode active material layer; and pressing the preliminary negative electrode to obtain the negative electrode having a finished negative electrode active material layer. A difference between the specific surface area of the preliminary negative electrode active material layer before pressing and that of the finished negative electrode active material layer after pressing is 0.5 m.sup.2/g to 1.0 m.sup.2/g. A negative electrode obtained by the method and a secondary battery including the negative electrode are also disclosed.

A flame-resistant polymer composite separator for use in a lithium battery, wherein the polymer composite separator comprises (a) a binder or matrix polymer; (b) 0.1% to 50% by weight of a lithium salt dispersed in the polymer; and (c) from 30% to 99% by weight of particles or fibers of an inorganic material or polymer fibers that are dispersed in or bonded by the polymer, wherein the polymer is a polymerization or crosslinking product of a reactive additive comprising (i) a first liquid solvent that is polymerizable, (ii) an initiator or crosslinking agent, and (iii) the lithium salt and wherein the polymer composite separator has a thickness from 50 nm to 100 μm and a lithium ion conductivity from 10.sup.−8 S/cm to 5×10.sup.−2 S/cm at room temperature.

An electrochemical cell comprising a first electrode separated from a second electrode by a shutdown separator. The first electrode can comprise a first current collector substrate having a first active material composite layered thereon. The second electrode can comprise a second current collector substrate parallel to the first current collector substrate. The second current collector substrate can have a second active material composite layered thereon. The first current collector substrate can have a first current collector tab extending from the first current collector substrate at a position along an axis parallel to a plane defined by the first current collector substrate. The second current collector substrate can have a second current collector tab extending from the second current collector substrate at a same position along the axis as the first current collector tab. A battery including the electrochemical cell and methods for manufacturing the battery are also described.

An electrode binder of a lithium ion secondary battery comprising an aqueous dispersion of: (a) a polyvinylidene binder; (b) a (meth)acrylic polymer dispersant; (c) a crosslinking agent comprising an aminoplast and/or a polycarbodiimide; and (d) an organic diluent. The (meth)acrylic polymer dispersant is prepared from a mixture of monomers comprising one or more carboxylic acid group-containing (meth)acrylic monomers and one or more hydroxyl group-containing (meth)acrylic monomers, and carboxylic acid groups on the (meth)acrylic polymer dispersant are at least partially neutralized with a base. The binder can be used in the assembly of electrodes of lithium ion secondary batteries.