7results about How to "Improve interface impedance" patented technology

The invention discloses a lithium battery positive plate as well as a preparation method and application thereof, and belongs to the technical field of lithium batteries. The positive electrode comprises a current collector and a positive electrode multi-layer structure attached to the current collector, the anode multilayer structure sequentially comprises a lithium manganese iron phosphate layer, a polycrystalline ternary material doped lithium manganese iron phosphate layer and a lithium manganate layer from top to bottom, and the lithium manganate layer is attached to the surface of the current collector; and the polycrystalline ternary material is nickel cobalt lithium manganate. The polycrystalline ternary material is compounded with the nano lithium manganese iron phosphate, and the nano lithium manganese iron phosphate particles are relatively fine and can be filled in gaps between the ternary positive electrode active material and the lithium manganate positive electrode material, so that the compaction density of the composite material and the contact between the particles are improved, and the internal resistance of a pole piece is reduced. And the active substance with a multi-layer structure improves the rate charging and rate discharging capabilities of the battery, and improves the safety performance and low temperature resistance of the battery.

The invention relates to the technical field of batteries, in particular to a positive electrode material, a preparation method and application thereof and an all-solid-state battery. The positive electrode material comprises an inner core and an outer core, wherein the inner core contains a nickel-rich ternary material; the interface modification layer is coated on at least part of the surface of the inner core, and the interface modification layer comprises lithium phosphorus oxide and metal sulfide. According to the positive electrode material, the interface impedance of the battery can be better reduced, the critical current density is improved, and the cycle life is prolonged.

The present invention provides a polymer electrolyte and a preparation method and application thereof, wherein the polymer electrolyte comprises a polymer and a lithium salt, wherein the polymer comprises a crosslinked product obtained by copolymerization of a compound represented by #imgabs0# and a compound represented by #imgabs1#, wherein in formula I, m is an integer selected from 2 to 20; and in formula II, R is selected from bistrifluoromethylsulfonyl imide, bisfluorosulfonyl imide, perchlorate, tetrafluoroborate, dioxalate borate, difluorooxalate borate or trifluoromethylsulfonate, and n is an integer selected from 1 to 10. The polymer electrolyte of the present invention has excellent ionic conductivity, lithium ion migration number and mechanical strength.

The invention provides a positive electrode active material and a preparation method thereof, a positive electrode plate, a battery and electric equipment, the positive electrode active material comprises a substrate and a coating layer, the coating layer is located on at least part of the surface of the substrate, the coating layer comprises a hydrophobic nanometer material, the positive electrode active material meets the condition that BET (2)-BET (1) is larger than or equal to 0.03 m < 2 > / g and smaller than or equal to 0.15 m < 2 > / g, and the BET (1) is larger than or equal to 0.03 m < 2 > / g and smaller than or equal to 0.15 m < 2 > / g. BET (1) is the directly tested specific surface area of the positive electrode active material, and BET (2) is the specific surface area of the positive electrode active material after ultrasonic dispersion. Therefore, the positive electrode active material with good hydrophobicity and less soft agglomeration among particles is obtained, and a battery with relatively high capacity, excellent rate capability and cycle performance is further obtained.

This invention discloses a high-strength, heat-resistant lithium-ion battery separator and its preparation method, belonging to the field of lithium-ion battery technology. The separator is a multilayer composite structure, comprising: a rigid porous framework membrane prepared from a rigid polymer material via thermally induced phase separation as a support layer; and a functional layer composited on the surface of the support layer. The functional layer is a gel electrolyte separator formed from a covalent organic framework material via electrospinning, containing a hierarchical porous network of micropores, mesopores, and macropores, and a flame retardant dispersed in the pores of the separator. The preparation method includes: thermally induced phase separation after melt blending, biaxial stretching and extraction, electrospinning surface deposition, flame retardant introduction, and hot pressing. The separator of this invention, through the synergistic effect of the rigid framework and the COFs gel layer, possesses high mechanical strength, high heat resistance, high ionic conductivity, and thermal runaway management functions, effectively improving the safety and cycle stability of semi-solid-state lithium-ion batteries.

The present application provides a silicon-based composite negative electrode material, the silicon-based composite negative electrode material comprising a silicon-based material core, and an antiperovskite solid electrolyte layer and a sulfur-based solid electrolyte layer sequentially covering the silicon-based material core, the antiperovskite solid electrolyte layer comprising Li 3‑t OH t A, wherein A is at least one of Cl, Br and I, and 0≤t≤2. The silicon-based composite negative electrode material has low impedance, high ion conductivity and outstanding electrochemical performance. The application also provides a preparation method of the silicon-based composite negative electrode material and an all-solid-state lithium battery.

The invention discloses an interface coated solid-state electrolyte and a lithium ion solid-state battery, the interface coated solid-state electrolyte comprises a solid-state electrolyte and an LMF interface modification layer arranged on the surface of the solid-state electrolyte; the thickness of the LMF interface modification layer is smaller than or equal to 60 nm. Through the arrangement of the LMF interface modification layer with the thickness of less than or equal to 60nm, under the synergistic effect of Li-Mg alloy and LiF in the LMF interface modification layer, the contact resistance between lithium metal and the electrolyte is effectively improved, the impedance of the interface-coated solid electrolyte can be effectively reduced by adopting simple and low-cost raw materials and a preparation process, and the interface-coated solid electrolyte has the advantages of low cost and high efficiency. Further, the electrochemical performance of the prepared lithium ion solid-state battery is effectively improved.