5results about How to "Guaranteed rate performance" patented technology

The invention relates to a non-aqueous electrolyte and a lithium ion battery. In order to develop the sulfur-free electrolyte and the lithium ion battery with good high-temperature and cycle performance, the cycle performance, the high-temperature performance and the rate performance of the lithium ion battery are improved by compounding the additive A and the boron-containing lithium salt additive; furthermore, other components in the non-aqueous electrolyte are combined, so that the lithium ion battery still has more excellent high-temperature performance and cycle performance and more excellent safety performance and electrochemical performance when the voltage is increased to 4.5 V or even higher while the high-temperature performance and cycle performance of the lithium ion battery under conventional voltage are ensured. Wherein the structural formula of the additive A is as follows: R1 is selected from alkylene, fluoroalkylene, alkenylene or fluoroalkenylene, and R2 is selected from fluoroalkyl or fluoroalkenyl; and the additive B is boron-containing lithium salt.

The application relates to the technical field of battery positive electrode materials, in particular to a synergistically modified high-voltage positive electrode material and a preparation method and application thereof, which comprises a bulk particle, a doped layer coated on the surface of the bulk particle and a coating layer coated on the surface of the doped layer; the bulk particle comprises lithium nickel cobalt manganese oxide; the doped layer is lithium nickel cobalt manganese oxide doped with fluorine elements in a bulk phase; and the coating layer comprises a lithium fluoride coating layer and lithium nickel cobalt manganese titanium oxide particles embedded in the lithium fluoride coating layer. The preparation method comprises the following steps: firstly, a nickel cobalt manganese hydroxide precursor is prepared by adopting a coprecipitation method; then, a doped layer and a coating layer are synthesized on the surface of the nickel cobalt manganese hydroxide precursor by adopting a solvothermal method; finally, calcination treatment is carried out to obtain the synergistically modified high-voltage positive electrode material. The synergistic modification strategy of bulk phase doping and surface coating effectively guarantees the stability of the interface and bulk structure, the preparation process is simple, and the electrochemical performance of the positive electrode material under high voltage, high cycle, high rate or high-temperature environment is improved.

The embodiment of the invention provides a positive plate, a preparation method thereof and a secondary battery. The positive plate comprises a current collector, a first positive active layer and a second positive active layer which are sequentially stacked, wherein the first positive electrode active layer comprises a first positive electrode active material, a liquid ion plastic crystal electrolyte, a first conductive agent and a first binder, and the second positive electrode active layer comprises a second positive electrode active material, a solid ion plastic crystal electrolyte, a second conductive agent and a second binder. The liquid ion plastic crystal electrolyte with high ionic conductivity is used in the first positive electrode active layer, and the solid ion plastic crystal electrolyte with high electrochemical stability is used in the second positive electrode active layer, so that partition collaborative optimization of an ion transmission channel and interface stability is realized; and the problem of contact inactivation of the positive active material due to volume change in the charging and discharging process is further avoided, so that the rate capability and long cycle performance of the all-solid-state battery under low test pressure are ensured.

The application provides a positive electrode material, a preparation method and application thereof, and has the chemical formula of Li a Fe b (PO4) c @C; wherein 0.95<=a<=1.10, 0.95<=b<=1.05, and 0.95<=c<=1.05; and the primary particles of the positive electrode material are twinned crystals composed of multiple single crystals. The application provides a positive electrode material, a preparation method and application thereof, and can balance the processing performance and electrochemical performance of the positive electrode material, and improve the rate performance and cycle performance of the positive electrode material.

This invention belongs to the field of lithium-ion capacitor technology, specifically relating to a lithium-ion capacitor with a porous carbon positive electrode and a hard carbon negative electrode, and its preparation method. Pretreated coal powder and KOH powder are carbonized in a tube furnace at a mass ratio of 1:(3~5) to obtain porous carbon as the positive electrode material; the pretreated coal powder is carbonized in a tube furnace at 1200~1600℃ to obtain hard carbon as the negative electrode material; the positive and negative electrode materials are assembled at a mass ratio of (1~3):1 to obtain a lithium-ion capacitor with good electrical performance. The porous carbon prepared by this invention has a hierarchical pore structure, high specific surface area, and suitable defect density, providing high specific capacitance; the hard carbon prepared by this invention has a composite structure of short-range ordered graphite-like microcrystals and amorphous carbon, which is conducive to rapid lithium-ion insertion / extraction, providing a capacity basis; the appropriate assembly ratio of the porous carbon positive electrode material and the hard carbon negative electrode material effectively improves the overall performance of the lithium-ion capacitor.