35results about How to "Good lithium conduction performance" patented technology

The invention relates to organic-inorganic all-solid-state composite electrolyte as well as preparation and application methods thereof, belonging to the field of lithium ion batteries. According to the organic-inorganic all-solid-state composite electrolyte, a highly-ordered three-dimensional connection network skeleton is formed by an inorganic fast lithium ion conductor, and a three-dimensional connection network is filled with a polymer and lithium salt. The organic-inorganic all-solid-state composite electrolyte which is flexible and has a controllable three-dimensional connection network structure is prepared. The electrolyte is high in lithium ion conductivity, wide in electrochemical window, good in mechanical property and stable to lithium metal. A lithium ion secondary battery assembled by a composite electrolyte membrane prepared by the method is high in capacity, stable in cycle performance, low in interface impedance and good in interface stability.

The invention discloses a composite diaphragm for a lithium-selenium battery and a preparation method of the composite diaphragm. The composite diaphragm is formed by smearing a coating material on an original diaphragm basal body, wherein the coating material consists of a titanium dioxide/porous carbon composite material, a conducting agent and a binder, and the titanium dioxide/porous carbon composite material is prepared by adopting a titanium-based metal organic framework as a precursor in a high-temperature carbonization manner. By adopting the composite diaphragm disclosed by the invention, a shuttle effect of poly-selenium ions generated in the charging and discharging process of the lithium-selenium battery between a selenium positive electrode and a lithium negative electrode can be effectively inhibited, and the cycling performance and the rate capability of the lithium-selenium battery can be remarkably improved. The preparation method is simple to operate, the composite diaphragm is low in cost and high in application potential and commercial value, and industrial implementation and mass production can be realized easily.

The invention provides a non-aqueous electrolyte and a lithium ion battery. The non-aqueous electrolyte comprises a solvent, an electrolyte lithium salt and a functional additive, and the functional additive comprises pentafluorophenyl vinyl sulfonate, 3-trifluoromethyl-5-methoxybenzonitrile and lithium difluorophosphate. When the electrolyte disclosed by the invention is applied to the lithium ion battery of a nickel-cobalt-manganese ternary material/graphite system, the high-voltage resistance of the lithium ion battery is improved, and the rate capability, the normal-temperature cycle, thehigh-temperature cycle and the high-temperature storage performance of the lithium ion battery are remarkably improved.

The invention discloses a carbohydrate modified lithium conductive polymer/inorganic hybrid electrolyte and application thereof. The electrolyte comprises a carbohydrate modified lithium conductive polymer and a lithium salt, wherein the carbohydrate modified lithium conductive polymer is obtained by crosslinking reaction or direct mixing of a carbohydrate compound and a lithium conductive polymer and/or a lithium conductive micromolecule compound. The electrolyte is compatible with high conductivity of an inorganic material and flexibility of a polymer material, has high lithium ion conductivity and good processability, and is suitably used for preparing a lithium ion battery, a lithium-sulfur or lithium-air battery and the like with large capacity and good cycle property; and the electrolyte is low in cost and is simple to prepare, and the selection range and the application field of a lithium battery material are expanded.

The invention provides an electrolyte capable of improving performance of a solid electrolyte membrane on the surface of a graphite electrode and a preparation method of the electrolyte. The electrolyte comprises an organic solvent and a solute salt; the organic solvent is a cyclic carbonic acid solvent; the solute salt is a lithium salt or mixed by a lithium salt and an ionic liquid; and the lithium salt accounts for 50-100 molar% of the whole solute. The invention also relates to an application of the electrolyte in preparation of a graphite-lithium half battery. The electrolyte disclosed inthe invention is stable in performance and simple in preparation; and when the electrolyte is applied to the battery, a more compact, stable and thinner SEI membrane can be formed on the surface of the graphite electrode, so that the capacity retention ratio of the battery can be improved, and cycle performance of the battery is improved.

The invention provides a preparation method of a lithium ion secondary battery. The method comprises the following steps of injecting non-aqueous electrolyte into a battery shell which is equipped with a battery pole shank, and forming the battery with the non-aqueous electrolyte, wherein the formation is divided into three steps, a first step is the constant-current constant-voltage charging in small current and low voltage, the second step is the constant-current constant-voltage charging of small current, and the third step is the constant-current charging; adding an additive into the non-aqueous electrolyte after the first step of the formation is ended and before the third step of the formation is started, wherein the additive is at least one of water, hydrofluoric acid and fluoro-ethylene carbonate. The battery prepared by utilizing the method is excellent in high-temperature stability and multiplying-power charging-discharging performance.

The invention relates to the field of solid-state electrolyte membranes, in particular to a preparation method of a solid-state composite electrolyte membrane supported by a synchronous substrate, and the method comprises the following steps of: a, extruding ultra-high molecular weight or high-density polyolefin molten slurry to form a casting sheet membrane; b, uniformly extruding the solid electrolyte molten slurry on the surface of the casting sheet membrane at the temperature T1 to form a solid electrolyte coating, thus obtaining a solid electrolyte coating-casting sheet substrate; c, stretching the solid electrolyte coating-casting sheet substrate at the temperature T2 to obtain a film; and d, carrying out hot-pressing shaping on the stretched film to control the thickness, and performing cooling to obtain the solid-state composite electrolyte membrane. The dipping effect of the solid electrolyte on a porous carrier is adjusted by controlling the stretching parameters, a continuous lithium conducting channel is formed, the lithium conducting capacity of the composite electrolyte is improved, meanwhile, the subsequent independent dipping step is omitted, and the production efficiency of the composite electrolyte membrane can be effectively improved.

The invention discloses a high-temperature and high-pressure electrolyte matched with a silicon-carbon negative electrode material lithium-ion battery. The electrolyte comprises an electrolyte lithiumsalt, a non-aqueous organic solvent and an additive, the electrolyte lithium salt comprises lithium hexafluorophosphate and lithium difluorosulfate borate, and the additive comprises a negative electrode film-forming additive pentafluorophenyl isocyanate and a positive electrode film-forming additive 4-trimethylsilyl-3-pentene-2-ketone compound. The lithium-ion battery electrolyte provided by theinvention can effectively improve the normal-temperature cycle, high-temperature cycle and high-temperature storage performance of the silicon-carbon battery under high voltage through a synergisticeffect generated by the combined use of the mixed lithium salt and multiple additives.

The invention relates to a positive pole piece, a preparation method thereof and a lithium ion battery. The preparation method of the positive pole piece comprises the following steps: step 1, premixing a ternary material with lithium manganate to prepare a cathode active material; step 2, mixing the cathode active material with a binder, a conductive agent and an organic solvent, and pulping the mixture to obtain a stable slurry; step 3, adding a certain amount of lithium carbonate into the slurry; step 4, coating an aluminum foil tape with the slurry, drying, rolling, and slicing, so as to obtain the positive pole piece. The positive pole piece prepared by adopting the preparation method provided by the invention improves the high temperature performance and the cycling stability of lithium ion batteries, greatly reduces the cost of materials, shortens the fusion time of the cathode material, the binder and the conductive agent and improves the production efficiency; besides, as a defined amount of lithium carbonate is added into the slurry, electrolyte decomposition in the cyclic process of batteries is effectively inhibited, and at the same time the solid electrolyte interphase (SEI) film is endowed with better viscoelasticity, the intercalation of lithium ions is facilitated, and both the electrochemical performance and the safety performance of batteries are further improved.

The invention discloses an electrolyte for a lithium battery, which comprises a lithium salt, a non-aqueous organic solvent and an additive, the additive is alkyl boric acid, and the weight percentage content of the additive is 0.5-2.0 wt%. The alkyl boric acid is one or a mixture of several of n-propyl boric acid, n-hexyl boric acid and n-octyl boric acid. The invention also discloses a preparation method of the electrolyte for the lithium battery and the lithium battery prepared by adopting the electrolyte. According to the electrolyte for the lithium battery, the preparation method of the electrolyte and the lithium battery, the problem that an existing lithium battery is low in charging and discharging frequency can be solved, and the electrolyte has the advantages of being good in cycling stability and slow in specific capacity attenuation.

The invention provides electrolyte, a negative electrode and a battery. The electrolyte contains lithium salt, an electrolyte solvent and an additive, wherein the added additive is a sulfate compoundin a structure provided by the invention. A film generated from the additive provided by the invention has excellent lithium guiding performance, so that the electrochemical polarization of the battery can be reduced, the low-temperature performance of the battery can be improved, the consumption of electrolyte can be impeded, the damaging of the negative electrode can be impeded, and the servicelife of the battery can be prolonged.

The invention provides a negative electrode active material, a preparation method of the negative electrode active material, a negative electrode material, a negative electrode and a lithium ion battery. The negative electrode active material comprises graphite particles and covering layers positioned on the surfaces of the graphite particles, wherein the covering layers comprise organic titaniumpolymers; the organic titanium polymers have a structure shown as a formula (I) in the description, wherein R is an alkyl group with the carbon atom number being 12; n is greater than or equal to 10 but smaller than or equal to 40. When the negative electrode active material is applied to the negative electrode, the stability and the lithium guide performance of an SEI film can be effectively improved, so that the prepared battery has reduced impedance and good high-temperature performance and low-temperature performance.