8results about How to "Reduce local current density" patented technology

This invention discloses a surface-modified current collector, an all-solid-state battery, its preparation method, and an electrical device. The surface-modified current collector includes a negative electrode current collector substrate, a lithium storage layer, and a lithiophilic layer arranged sequentially along the thickness direction. The lithium storage layer has a plurality of micropores oriented perpendicularly to and / or inclined to the surface of the negative electrode current collector substrate. The lithium storage layer includes a conductive micropore template with a micropore structure having a plurality of micropores with the same orientation as the micropores and a vanadium nitride layer disposed on the surface of the conductive micropore template and the inner wall of its micropore structure. This lithium storage layer constitutes a three-dimensional conductive framework, which can guide lithium ions to transport longitudinally or tend to transport longitudinally and deposit uniformly, suppress lithium dendrite growth, and alleviate volume expansion stress during cycling. The lithiophilic layer provides low nucleation overpotential sites, further promoting uniform lithium deposition. Through the synergy of the above layers, uniform lithium deposition can be effectively achieved, and volume expansion stress during cycling can be dispersed and absorbed, significantly improving the cycle performance and safety of the battery.

The present application discloses an interface layer with high diffusion coefficient, the raw material of the interface layer includes carbon material, organic compound with thioamide group. The interface layer of the present application can effectively reduce the local current density of anode and improve the diffusion ability of Li + The interface layer of the present application can effectively prevent the accumulation of electric charge, promote the diffusion ability of anode and improve the diffusion ability of Li + The interface layer of the present application can effectively prevent the accumulation of electric charge, promote the diffusion ability of anode and improve the diffusion ability of Li The interface layer of the present application can be used in batteries to improve the electrical performance and safety performance of the batteries.

This invention belongs to the field of aqueous secondary batteries, specifically relating to a three-dimensional zinc / zinc oxalate anode material, its preparation method, and its application. The three-dimensional zinc / zinc oxalate anode material includes a zinc metal substrate and a three-dimensional protective layer. The zinc metal substrate is a commercially available zinc metal foil, and the three-dimensional protective layer is a zinc oxalate interface material formed in situ by the displacement reaction of the zinc metal substrate with an oxalic acid solution. This invention uses low-temperature ultrasound as the reaction condition to deposit zinc oxalate on the surface of the zinc metal foil, forming a tightly bonded and uniform three-dimensional protective interface in situ. Its specific surface area is more than 10 times larger than that of the original zinc metal foil, effectively reducing local current density to suppress dendrite growth. Simultaneously, the dense zinc oxalate protective layer isolates the active zinc from the aqueous electrolyte to suppress corrosion and hydrogen evolution side reactions, thereby improving the cycle performance of the zinc metal anode in aqueous secondary batteries.

The invention provides a semiconductor device structure and a preparation method thereof, and the semiconductor device structure comprises a substrate which is provided with a contact point; the dielectric layer is formed on the substrate; the contact hole is formed in the dielectric layer, and the contact hole exposes a contact point; the metal layer is formed on the side wall and the bottom of the contact hole; the ratio of the first thickness of the metal layer on the side wall of the contact hole to the second thickness of the metal layers on the two sides of the top of the contact hole is larger than 0.30, and the first thickness of the metal layer on the side wall of the contact hole is larger than 300 nanometers. By controlling the thickness of the dielectric layer, the angle of the contact hole, the thickness of the side wall metal of the contact hole and the ratio of the thickness of the side wall metal to the thickness of the top metal and cooperatively controlling the structural parameters, the side wall covering thickness of the metal layer can be effectively and remarkably improved, the local current density is reduced, and therefore the electromigration life and reliability of the device are greatly improved.

This invention provides a cellulose-based sodium-ion battery separator with a double-layer structure and its preparation method, belonging to the field of sodium-ion battery separator technology. The separator of this invention uses micron-sized cellulose fibers, nano-sized cellulose fibers, aramid precipitated fibers, aramid chopped fibers, and nano-Al2O3 as main raw materials. Through a dual-channel synchronous molding process based on wet nonwoven fabric technology, an integrated double-layer composite separator is formed, consisting of a rigid corrosion-resistant protective layer facing the positive electrode and a dense elastic buffer layer facing the negative electrode. The separator of this invention exhibits excellent thermal stability, extremely high electrolyte wettability, good mechanical strength, and a controllable porous structure, effectively improving the safety and electrochemical performance of sodium-ion batteries. The preparation process uses water as a medium, is environmentally friendly, and is easy to scale up for production.

The invention relates to the photovoltaic field, and discloses a back contact solar cell and a back side coarsening method thereof. In the first direction, first type regions and second type regions which are alternately distributed at intervals are arranged on the back surface of the substrate; in the second direction, a dielectric layer and a first type polycrystalline silicon layer are sequentially arranged on the back surface of the substrate in the first type region from inside to outside, and a dielectric layer and a second type polycrystalline silicon layer are sequentially arranged on the back surface of the substrate in the second type region; the surfaces, deviating from the substrate, of the first type polycrystalline silicon layer and the second type polycrystalline silicon layer are rough surfaces; a first type region electrode and a second type region electrode. The surface roughness of the first type polycrystalline silicon layer and the second type polycrystalline silicon layer away from the substrate is large, the adhesive force of the first type region electrode and the second type region electrode can be improved, meanwhile, the local current density and the contact resistance are reduced, the light scattering capacity of the surface of the first type polycrystalline silicon layer and the second type polycrystalline silicon layer away from the substrate can be improved, and the service life of the device is prolonged. And the cell conversion efficiency is improved.

The invention discloses a preparation method of a metal negative electrode material of a sodium secondary battery and the sodium secondary battery. The preparation method comprises the following steps: S1, carrying out heteroatom surface modification treatment on a pure-phase continuous carbon nanotube film; s2, preparing a sodium-containing molten liquid; s3, dipping the carbon nanotube film subjected to surface modification treatment in the step S1 into a sodium-containing melt liquid; and S4, rolling the carbon nanotube film impregnated in the step S3, coating and rolling to obtain the ultra-thin sodium metal negative electrode coiled material, so that the energy density and the safety of the battery can be remarkably improved, and the cycle life of the battery can be remarkably prolonged.

The application discloses a kind of zinc negative electrode PVA / porous carbon array protective layer femtosecond laser preparation method, zinc negative electrode material and its application, to solve zinc negative electrode dendrite growth, corrosion passivation, hydrogen evolution side reaction highlights and the problems such as existing protective layer preparation process is complex, structure regulation precision is low.The preparation method includes three steps: S1 PVA is mixed with deionized water, heated and stirred to form a semi-thick solution;S2 the solution is uniformly coated on the surface of zinc foil, and a PVA protective layer is formed after drying;S3 PVA protective layer is decomposed by femtosecond laser, and a porous PVA / porous carbon array composite protective layer is prepared.The composite protective layer enhances the interface stability through PVA, and the synergistic effect of porous carbon guiding zinc ion uniform deposition effectively inhibits dendrite growth and corrosion reaction.The application process is simple, raw materials are environmentally friendly and cost is relatively low, suitable for mass production, and provides key technical support for commercialization of aqueous zinc ion battery.