An electrochemical cell is provided, which includes a cathode comprising a three dimensional (3D) porous cathode structure, an anode, an electrolyte separator, comprised of a ceramic material, located between the cathode and the anode, and a cathode current collector, wherein the cathode is located between the cathode current collector and the electrolyte separator. The 3D porous cathode structure includes ionically conducting electrolyte strands extending through the cathode from the cathode current collector to the electrolyte separator, pores extending through the cathode from the cathode current collector to the electrolyte separator, and an electronically conducting network extending on sidewall surfaces of the pores from the cathode current collector to the electrolyte separator.

Disclosed are compositions, devices, systems and fabrication methods for stretchable composite materials and stretchable electronics devices. In some aspects, an elastic composite material for a stretchable electronics device includes a first material having a particular electrical, mechanical or optical property; and a multi-block copolymer configured to form a hyperelastic binder that creates contact between the first material and the multi-block copolymer, in which the elastic composite material is structured to stretch at least 500% in at least one direction of the material and to exhibit the particular electrical, mechanical or optical property imparted from the first material. In some aspects, the stretchable electronics device includes a stretchable battery, biofuel cell, sensor, supercapacitor or other device able to be mounted to skin, clothing or other surface of a user or object.

Provided is a secondary battery that can sufficiently suppress a leakage current even when conductive foreign matter passes through a separator to cause a minute short-circuit. The secondary battery according to an aspect of the present disclosure comprises: a positive electrode; a negative electrode; and a separator interposed between the positive electrode and the negative electrode, wherein each of the positive electrode and the negative electrode has a current collector and a mixed material layer formed on the surface of the current collector. At least one of the positive electrode and the negative electrode has a semiconductor layer formed substantially over the entire surface of the mixed material layer and having a higher resistance than the mixed material layer.

Provided is a composite thin film current collector for a battery or supercapacitor, the thin film comprising graphene sheets dispersed in or bonded by an electron-conducting polymer network (also referred to as conducting network polymer, crosslinked polymer, or hydrogel polymer) wherein the composite thin film has a thickness from 2 nm to 500 μm and an electrical conductivity from 10.sup.−4 to 10.sup.4 S/cm and wherein the graphene sheets occupy from 10% to 99% by weight and the polymer network from 1% to 90% by weight of the total composite weight.

An all solid battery includes: a solid electrolyte layer; a first electrode layer that is formed on a first main face of the solid electrolyte layer; a first electric collector layer that is formed on a face of the first electrode layer, the face being opposite to the first main face; a second electrode layer that is formed on a second main face of the solid electrolyte layer; and a second electric collector layer that is formed on a face of the second electrolyte layer, the face being opposite to the second main face, wherein at least one of the first electric collector layer and the second electric collector layer includes Pd and board-shaped graphite carbon, wherein a volume ratio of Pd and the board-shaped graphite carbon in the at least one of the first electric collector layer and the second electric collector layer is 20:80 to 80:20.

A positive current collector, a secondary battery, and an electrical device are provided. In some embodiments, the positive current collector includes: a support layer; and a conductive layer located on at least one surface of the support layer, where the conductive layer includes a first metal portion configured to connect to a tab, where, along a thickness direction of the conductive layer, the first metal portion includes at least three sublayers, and melting points of the at least three sublayers rise stepwise in ascending order of distance from the support layer. In the embodiments of this application, the first metal portion includes at least three sublayers, and the melting points of the at least three sublayers rise stepwise in ascending order of distance from the support layer, thereby helping increase a bonding force between the conductive layer and the support layer and reducing the probability of peel-off and delamination between the layers.

This application provides a current collector and a preparation method thereof, a secondary battery containing such current collector, a battery module, a battery pack, and an electric apparatus. The current collector in this application includes a support layer, a binder layer, and a metal layer, where the binder layer is arranged between the support layer and the metal layer, the binder layer includes an organic binder and inorganic particles, a thickness D.sub.0 of the binder layer is 1.0-5.0 μm, optionally 1.0-3.0 μm; and the inorganic particles include large particles with a median particle size D.sub.50large and small particles with a median particle size D.sub.50small, and the median particle sizes of the large particles and the small particles satisfy the following relationships: D.sub.50large>D.sub.50small; D.sub.50large=(0.5-0.9)×D.sub.0; and D.sub.50small=(0.1-0.4)×D.sub.0.

An electrode improved for achieving a storage battery having both a high electrode strength and favorable electrode conductivity is provided. The electrode includes graphene and a modified polymer in an active material layer or includes a layer substantially formed of carbon particles and an active material layer including a modified polymer over a current collector. The modified polymer has a poly(vinylidene fluoride) structure and partly has a polyene structure or an aromatic ring structure. The polyene structure or the aromatic ring structure is sandwiched between poly(vinylidene fluoride) structures.

A monolithic ceramic electrochemical cell housing is provided. The housing includes two or more electrochemical sub cell housings. Each of the electrochemical sub cell housing includes an anode receptive space, a cathode receptive space, a separator between the anode receptive space and the cathode receptive space, and integrated electron conductive circuits. A first integrated electron conductive circuit is configured as an anode current collector within the anode receptive space. A second integrated electron conductive circuit is disposed as a cathode current collector within the cathode receptive space.

Provided is a battery module including: multiple cylindrical batteries each including: a shaft core; a set of wound electrodes including an electrode stack wound around the shaft core and including a positive electrode, a negative electrode, and an electrolyte provided between the positive and negative electrodes stacked; a first fastener provided at a first axial end of the shaft core; and a second fastener provided at a second axial end of the shaft core, adjacent ones of the cylindrical batteries being fastened together with the first and second fasteners.