5results about How to "Improve low temperature cycle performance" patented technology

The application relates to a preparation method and application of a low-temperature-resistant gel polymer electrolyte, and belongs to the technical field of polymer electrolytes.The application solves the technical problem of providing a preparation method of a low-temperature-resistant gel polymer electrolyte suitable for a lithium metal battery.The method uniformly mixes an ether electrolyte, allyl potassium trifluoroborate, a crosslinking agent such as pentaerythritol tetraacrylate and fluorinated ethylene carbonate to obtain a precursor solution;uniformly mixes azobisisobutyronitrile and the precursor solution to obtain a reaction solution;and then performs a warming reaction to obtain a low-temperature-resistant gel polymer electrolyte.The application significantly improves the frost resistance of the electrolyte by introducing an anion conductor, can realize good low-temperature resistance, and improves the low-temperature cycle performance.The electrolyte has high conductivity, overcomes the defect of low ion conductivity of a conventional polymer electrolyte at low temperature;has high lithium ion transference number, effectively solves the defect of low transference number of a polymer electrolyte Li + +.

This invention discloses the use of a class of polysubstituted cyclic ether compounds as solvents for lithium-ion battery electrolytes. The polysubstituted cyclic ether compounds are alkyl-substituted cyclic ether solvents. These polysubstituted cyclic ether solvents have lower dielectric constants and lower ion desolvation energies, and exhibit good stability with lithium metal / graphite anodes. More importantly, these polysubstituted cyclic ether compounds have no special restrictions on the type of lithium salt. Using these polysubstituted cyclic ether compounds can significantly improve the low-temperature performance of batteries, thus broadening their applicability.

This invention discloses a high-safety, high-cycle-life in-situ cured gel polymer electrolyte and its preparation method, belonging to the field of lithium-ion battery technology. The electrolyte is formed by in-situ polymerization of a gel precursor solution inside the battery triggered by an energy field. The precursor solution contains acrylamide and / or methacrylamide polymerizable monomers, multifunctional acrylate and / or methacrylate crosslinking agents, phosphorus-containing polymerizable flame-retardant components, an initiator, lithium salt, and an organic solvent. The preparation method includes preparing the precursor solution, injecting it into the pores of the battery cell, and in-situ curing triggered by heat or ultraviolet light. Through the synergistic effect of in-situ gelation and gradient electrodes, continuous and stable ion transport channels and flame-retardant networks are constructed within the electrode pores, thereby simultaneously improving the battery's abuse safety and low-temperature cycle life.

The application relates to the technical field of batteries, and provides an electrochemical device, which comprises a positive electrode sheet, a negative electrode sheet and a separator, the negative electrode sheet comprises a negative electrode current collector and a negative electrode active layer located on at least one side surface of the negative electrode current collector, the negative electrode active layer comprises a negative electrode active material, the negative electrode active material comprises a silicon-based material; the separator comprises a base film and a ceramic layer arranged on at least one side surface of the base film, the ceramic layer comprises a plurality of interval distributed stripes and a plurality of interval areas located in the middle of adjacent stripes, the width of the stripe is A1 mu.m, and the width of the interval area is A2 mu.m; the electrochemical device satisfies the relationship formula 0.06 <= A * C <= 0.9, wherein A is A1 / A2, and C is the mass content of silicon elements in the negative electrode active material. The scheme effectively alleviates the volume expansion of the silicon negative electrode, improves the charging and discharging efficiency, reduces the minimum residual power level capable of effective discharging, and improves the available discharge depth.

The application discloses a water-based electrolyte and a zinc ion hybrid capacitor comprising the water-based electrolyte. The water-based electrolyte is a water-based electrolyte for a zinc ion hybrid capacitor, and comprises a zinc salt, an electrolyte additive and water. The electrolyte additive comprises a first additive and a second additive. The first additive is an organic antifreezing agent, and the second additive is a heterocyclic nonane. The volume fraction of the organic antifreezing agent in the water-based electrolyte is greater than 0.1% and less than 40%. The water-based electrolyte of the application uses the organic antifreezing agent and the heterocyclic nonane as additives, and the two cooperate with each other. The water-based electrolyte can not only prevent freezing and avoid ice formation, but also modify the zinc negative electrode interface, reduce the Zn 2+ reduction rate, alleviate concentration polarization, thereby facilitating inhibition of dendrite growth, and can also inhibit the side reaction of the zinc negative electrode, thereby improving the low-temperature cycle performance of the zinc ion hybrid capacitor.