A secondary battery includes a positive electrode sheet which includes a positive-electrode current collector, a positive-electrode active material layer, and a coating layer arranged between the positive-electrode current collector and the positive-electrode active material layer. The coating layer includes a conductive agent and a copolymer.

A current collector, an electrochemical device containing the current collector, and an electronic device. The current collector includes a polymer substrate material and a conductive material. An electron resistivity of the current collector in an X-Y in-plane direction is 10 Ω.Math.cm to 1000 Ω.Math.cm, and an electron resistivity of the current collector in a Z direction is 0.01 Ω.Math.cm to 30 Ω.Math.cm. The current collector according to this application is excellent in oxidation resistance, reduction resistance, ionic insulation, mechanical strength, thermal stability, increases the energy density of bipolar electrochemical devices, and is more cost-effective and more suitable for mass production.

The present invention relates to a lithium secondary battery comprising: a current collector comprising a structure in a fabric form in which fiber bundles are cross-woven, wherein each of the fiber bundles is formed of sets of fiber yarns and each of the fiber yarns includes a polymer fiber and a metal layer surrounding the polymer fiber; and an electrode including an active material layer disposed on at least one surface of the current collector.

A conductive film, a fabrication method of the conductive film, and a lithium-ion battery (LIB) are provided. The fabrication method includes: S10: selecting a support layer, and plating a first metal layer on upper and lower surfaces of the support layer, respectively; S20: compounding a first film on a surface of one of the first metal layers, and compounding a second film on a surface of the other one of the first metal layers; S30: compounding a third film on surfaces of the first film and the second film, and etching a plurality of circular holes penetrating through the third film and the second film; S40: plating a second metal layer on an outer surface of the third film and an inner wall of the circular hole; S50: fabricating a composite film; and S60: plating a third metal layer on upper and lower surfaces of the composite film.

A secondary battery includes a rectangular exterior body having an opening and containing a first electrode assembly and a second electrode assembly, a sealing plate sealing the opening, and a positive-electrode current collector. The sealing plate has an electrolytic solution introduction hole. The first electrode assembly includes a first insulating sheet on an outermost surface thereof adjacent to the second electrode assembly. The second electrode assembly includes a second insulating sheet on an outermost surface thereof adjacent to the first electrode assembly. A first tape is attached to both an outermost surface of a first positive-electrode tab group and the first insulating sheet. A second tape is attached to both an outermost surface of a second positive-electrode tab group and the second insulating sheet. At least one of the first tape and the second tape is located to face the electrolytic solution introduction hole.

An electrode, a lithium battery including the same, and a method of manufacturing the electrode. The electrode includes an electrode current collector, and an electrode active material layer on at least one surface of the electrode current collector, wherein the electrode active material layer includes a first electrode active material, a second electrode active material, and a binder, the electrode active material layer includes a first cluster, and the first cluster is an agglomerate including a plurality of first electrode active materials, one surface of the electrode active material layer includes a first domain including the first cluster, and an area of the first domain is about 15% to about 60% of the total area of the one surface of the electrode active material layer.

The concepts described herein provide a hybrid metal/polymer current collector for a battery cell electrode that includes a collector body joined to a tab portion and encased in an electrically conductive overlay, and an associated method of manufacture. The tab portion is fabricated from a homogeneous electrically conductive material, the collector body is fabricated from a polymer, and the collector body is joined to the tab portion at a junction.

A composite current collector includes a support layer and a conductive layer. The support layer has two surfaces opposite to each other along a thickness direction. The conductive layer is provided on the two surfaces and includes a first portion and a second portion. The first portion includes a first sub-portion and a second sub-portion provided on the two surfaces, respectively. The second portion includes a third sub-portion and a fourth sub-portion. The third sub-portion and the first sub-portion are integrally provided. The fourth sub-portion and the second sub-portion are integrally provided. The third sub-portion and the fourth sub-portion both project from the support layer. The third sub-portion and the fourth sub-portion are affixed to each other and fused as a whole.

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.

According to one embodiment of the present disclosure, a free-standing film for dry electrode, comprising: a binder, an active material and a conductive material, wherein the free-standing film has a tensile strength of 2000 gf/cm.sup.2 or more based on a thickness of 200 μm.