A facile method is based on a pack-cementation process using large-area copper foil instead of copper powder. By controlling a pack-cementation time and an amount of alloying element (e.g., aluminum), a hierarchical microporous or nanoporous copper can be created. When coated with tin active material, the hierarchical microporous or nanoporous copper can be used as an advanced lithium-ion battery anode. A coin-cell test exhibited a four-fold higher areal capacity (e.g., 7.4 milliamp-hours per square centimeter without any performance degradation up to 20 cycles) as compared to a traditional graphite anode.

Provided is a technique for capturing transition metal ions, such as cobalt ions, in a secondary battery that elute from a positive electrode active material and for preventing deposition of transition metal at a negative electrode. A composition for a lithium ion secondary battery porous membrane that contains non-conductive particles and a binding material is provided. The binding material includes a polymer A including an aliphatic conjugated diene monomer unit in a proportion of greater than 85 mass % and a polymer B including a (meth)acrylic acid ester monomer unit in a proportion of at least 60 mass %. A mass basis ratio of content of the polymer A relative to content of the polymer B is at least 0.2 and no greater than 9.0.

Provided is a technique for capturing transition metal ions, such as cobalt ions, in a secondary battery that elute from a positive electrode active material and for preventing deposition of transition metal at a negative electrode. A composition for a lithium ion secondary battery porous membrane that contains non-conductive particles and a binding material is provided. The binding material includes a polymer A including an aliphatic conjugated diene monomer unit in a proportion of greater than 85 mass % and a polymer B including a (meth)acrylic acid ester monomer unit in a proportion of at least 60 mass %. A mass basis ratio of content of the polymer A relative to content of the polymer B is at least 0.2 and no greater than 9.0.

A three-dimensional porous composite electrode includes a three-dimensional porous current-collector and an active material layer including an active material and having a three-dimensional structure along a surface of the three-dimensional porous current-collector. The three-dimensional porous current-collector extends along a first direction, includes a current-collecting material and has a porosity gradient along a second direction perpendicular to the first direction. The three-dimensional porous composite electrode has a ratio gradient of the active material to the current-collecting material along the second direction.

A three-dimensional porous composite electrode includes a three-dimensional porous current-collector and an active material layer including an active material and having a three-dimensional structure along a surface of the three-dimensional porous current-collector. The three-dimensional porous current-collector extends along a first direction, includes a current-collecting material and has a porosity gradient along a second direction perpendicular to the first direction. The three-dimensional porous composite electrode has a ratio gradient of the active material to the current-collecting material along the second direction.

Provided herein are three-dimensional ion transport networks and current collectors for electrodes of electrochemical cells. Exemplary electrodes include interconnected layers and channels including an electrolyte to facilitate ion transport. Exemplary electrodes also include three dimensional current collectors, such as current collectors having electronically conducting rods, electronically conducting layers or a combination thereof.

Provided herein are three-dimensional ion transport networks and current collectors for electrodes of electrochemical cells. Exemplary electrodes include interconnected layers and channels including an electrolyte to facilitate ion transport. Exemplary electrodes also include three dimensional current collectors, such as current collectors having electronically conducting rods, electronically conducting layers or a combination thereof.

The present invention relates to a hierarchical composite structure comprising an open cell graphene foam or graphene-like foam, wherein the graphene foam or graphene-like foam is coated with a conductive nanoporous spongy structure and wherein at least 10% v/v of the hollow of the pores of the graphene foam or graphene-like foam is filled with the conductive nanoporous spongy structure. The invention also relates to a process for preparing a hierarchical composite structure wherein a conductive nanoporous spongy structure is electrodeposited so as to coat the open-cell graphene foam or graphene-like foam and to partially fill the hollow of the pores of the graphene foam or graphene-like foam.

Provided is a method of manufacturing a solid electrolyte sheet, and a solid electrolyte sheet that can improve battery output performance, and can suppress interfacial peeling and short-circuiting between the solid electrolyte layer and the electrode layer. A method of manufacturing a solid electrolyte sheet includes: a first step of a base with coating slurry containing a solid electrolyte; a second step of drying the slurry on the base to form a solid electrolyte layer; a third step of stacking a sheet-like three-dimensional structure on the top surface of the solid electrolyte layer; a fourth step of coating the inside and top of the three-dimensional structure with slurry containing a solid electrolyte; and a fifth step of drying the slurry coated on the inside and on the top of the three-dimensional structure to obtain a solid electrolyte sheet filled with the solid electrolyte.

A positive electrode plate for a lead-acid battery includes: a punched grid having grid crosspieces; and a positive electrode material. A corner portion of the grid crosspiece of the punched grid in a cross section perpendicular to an extending direction of the grid crosspiece is deformed, and a density of the positive electrode material after being subjected to formation is 4.1 [g/cm.sup.3] or more.