698 results about "Diethyl carbonate" patented technology

A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one nitrate additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture that includes ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate. The preferred additive is an organic alkyl nitrate compound.

A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one nitrite additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture that includes ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate. The preferred additive is an alkyl nitrite compound.

A nonaqueous electrolyte secondary battery includes: an outer housing; a nonaqueous electrolyte filled in the outer housing, a positive electrode housed in the outer housing, a negative electrode housed in the outer housing and a separator disposed between the negative electrode and the positive electrode. The nonaqueous electrolyte comprises a nonaqueous solvent including diethyl carbonate and at least one of ethylene carbonate and propylene carbonate, and the nonaqueous electrolyte has a content of the diethyl carbonate of from 80 to 95% by volume. The positive electrode comprises a positive electrode active substance having a positive electrode potential in a full charged state of 4.4 V or higher with respect to a potential of metallic lithium. The negative electrode comprises a negative electrode active substance having a negative electrode potential in a full charged state of 1.0 V or higher with respect to a potential of metallic lithium.

The invention relates to a non-aqueous electrolyte for high-voltage lithium ion batteries, which is prepared from the following raw materials in percentage by weight: 70-85% of carbonate, 3-20% of functional additive and 11-17% of lithium hexafluorophosphate. The carbonate is one or mixture of more of ethylene carbonate, propylene carbonate, butylene carbonate, dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylethyl carbonate, methyl propyl carbonate and methyl butyl carbonate; and the functional additive is one or mixture of more of 0.5-10% of negative pole film-forming additive, 0.5-10% of high-temperature additive, 0.5-10% of positive pole film-forming additive, 0.5-10% of high-voltage additive and 0.001-2% of stability additive. The invention solves the problem of adaptation of the lithium ion battery electrolyte to the 4.35V high-voltage battery positive/negative pole, and provides an electrolyte for high-voltage batteries, which has the advantages of high cycle life, low inflation rate and favorable high-temperature properties.

The invention discloses a lithium-ion secondary battery and an electrolyte thereof. The electrolyte comprises a solvent, lithium salt and a film forming additive, wherein the solvent comprises a first solvent and a second solvent; the first solvent comprises linear carboxylic ester and ethylene carbonate; the second solvent is one or more of ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate and propylene carbonate; and the film forming additive is one or more of fluoroethylene carbonate, vinylene carbonate, 1,3-propane suhone, succinonitrile, adiponitrile, lithium bis(oxalato)borate, and lithium oxalyldifluoroborate. Due to the collocation of linear carboxylic ester and ethylene carbonate, a solvent system with a higher dielectric constant and low viscosity is obtained; the film forming additive improves poor compatibility between linear carboxylic ester and graphite; and finally the lithium-ion secondary battery adopting the electrolyte presents high-power discharge capacity, excellent high-temperature cycling stability and low-temperature charge and discharge properties.

A secondary battery is comprised of a positive electrode, a negative electrode formed from a lithium storage material, and a non-aqueous electrolyte. The non-aqueous electrolyte includes a lithium salt, non-aqueous aprotic solvent(s), such as ethylen carbonate, propylene carbonate, dimethyl carbonate, ethymethyl carbonate and diethyl carbonate, and a small percentage of at least one organic additive. The negative electrode may comprise a carbon such as graphite, and the positive electrode may comprise a lithiated metal oxide or phosphate, such as LiCoO₂, LiNiO₂, LiMn₂O₄, LiFePO₄, or mixtures thereof. The organic additives have one or more unsaturated bonds activated with respect to oxidation by electron-pushing alkyl groups. They are in most cases known to be able to undergo polymerization reactions, such as an anodically induced polymerization especially under certain conditions. The additives are oxidized at the cathode at a potential of more than 4.3 V vs. Li/Li⁺. With these additives in amounts of 0.001 to 10%, a passivation layer is formed on the cathodes, and the sensitiveness of the battery against overcharge is reduced. The electrolyte mixtures do not deteriorate the properties of the battery anodes.

Provided are a binder composition which has high electrolyte resistance characteristics, and a secondary battery which uses a positive electrode using the binder composition for high-temperature cycle characteristics. [Solution] The binder composition for the secondary battery positive electrode according to the present invention contains a polymerized unit which contains a nitrile group; a polymerized unit of (meth) acrylic acid ester; a polymerized unit which contains a hydrophilic group; and a polymerized unit of linear alkylene having a carbon number of at least four. In a mixed solvent in which a volume ratio EC:DEC between ethylene carbonate (EC) and diethyl carbonate (DEC) at 20° C. is 1:2, a degree of swelling with respect to an electrolyte in which LiPF₆ is dissolved to have a concentration of 1.0 mol/L is between 100% and 500%.

Diphenyl carbonate is produced by reacting phenol with diethyl carbonate in a series of fixed bed reactors each of which is connected at different position on a distillation column via side draw and return streams. The composition of material in a distillation column varies along the length of the column, which is predictable under a given set of conditions of temperature and pressure, thus withdrawing streams at different stages in the column, allows the reactor receiving the feed from a particular stage to be operated under conditions to maximize the desired reaction, while allowing the unreacted or byproduct to go back into the distillation and be sent to a stage (by the equilibrium of the distillation) where they are favorably treated in a reactor.

A rechargeable lithium cell comprising a cathode, an anode, a non-flammable quasi-solid electrolyte containing a lithium salt dissolved in a mixture of a liquid solvent and a liquid additive having a salt concentration from 1.5 M to 5.0 M so that said electrolyte exhibits a vapor pressure less than 0.01 kPa, a vapor pressure less than 60% of the vapor pressure of the liquid solvent alone, a flash point at least 20 degrees Celsius higher than the flash point of the liquid solvent alone, a flash point higher than 150° C., or no flash point, wherein the liquid additive is selected from Hydrofluoro ether (HFE), Trifluoro propylene carbonate (FPC), Methyl nonafluorobutyl ether (MFE), Fluoroethylene carbonate (FEC), Tris(trimethylsilyl)phosphite (TTSPi), Triallyl phosphate (TAP), Ethylene sulfate (DTD), 1,3-propane sultone (PS), Propene sultone (PES), Diethyl carbonate (DEC), Alkylsiloxane (Si—O), Alkylsilane (Si—C), liquid oligomeric silaxane (—Si—O—Si—), Tetraethylene glycol dimethylether (TEGDME), or a combination thereof.

A lithium ion electrochemical cell having high charge/discharge capacity, long cycle life and exhibiting a reduced first cycle irreversible capacity, is described. The stated benefits are realized by the addition of at least one dicarbonate additive to an electrolyte comprising an alkali metal salt dissolved in a solvent mixture that includes ethylene carbonate, dimethyl carbonate, ethylmethyl carbonate and diethyl carbonate. The preferred additive is an alkyl dicarbonate compound.

The invention relates to a method for synthesizing methylethyl carbonate by ester exchange of dimethyl carbonate and diethyl carbonate, which is implemented by carrying out synthetic reaction of methylethyl carbonate on raw materials dimethyl carbonate and diethyl carbonate by using an imidazole ionic liquid as a catalyst at certain reaction temperature under ordinary pressure for some reaction time. The catalyst consumption is only 0.2-2 wt% of the dimethyl carbonate; the ionic liquid catalyst has high catalytic activity in the reaction process, the maximum yield of methylethyl carbonate is up to 62.31%, and the selectivity is 100%; and the catalyst can be recycled for cyclic utilization after being subjected to simple treatment after reaction, has the advantages of long service life and no pollution, and greatly lowers the preparation cost of methylethyl carbonate.

A binder for electrode of lithium ion secondary battery, comprised of a copolymer composed of 15 to 80 weight % of units from ethylenically unsaturated monomer (A) whose homopolymerization yields a polymer soluble in N-methylpyrrolidone (NMP) and 20 to 85 weight % of units from ethylenically unsaturated monomer (B) whose homopolymerization yields a polymer insoluble in NMP, which copolymer exhibits a swelling degree of 4 or below, in an electrolyte obtained by dissolving LiPF₆ in the concentration of 1 mol/liter into a solvent of 1:2 (volume ratio at 20° C.) mixture of ethylene carbonate (EC) and diethyl carbonate (DEC) . This binder for electrode of lithium ion secondary battery enables obtaining an electrode having a flexible electrode layer excelling in binding properties with industrial advantage.

The synthesis method of methyl ethyl carbonate belongs to the technical field of organic compounds synthesized by ester exchange. Dimethyl carbonate and diethyl carbonate, or dimethyl carbonate and ethanol are used as raw materials to perform ester exchange in the presence of catalyst. The reaction mode comprises two kinds of fixed bed continuous reaction and kettle-type reaction. The catalyst issolid alkali catalyst in which the carrier is active carbon, carbon molecular sieve or mesoporous carbon and the active component is Na2O, K2O, MgO, CaO, SrO or BaO. In the process of fixed bed continuous synthesis, the catalyst is stable without inactivation after long-term use, thereby retaining the high yield of the methyl ethyl carbonate, simplifying the production process, and achieving environmental friendliness and energy conservation. In the kettle-type reaction, the catalytic efficiency is high, the catalyst can be recovered by simple filtering and re-sintering, and the target product can be obtained in short time with high yield.

Disclosed is a sodium-ion secondary battery having excellent charge and discharge efficiencies as well as excellent charge and discharge characteristics, wherein charging and discharging can be repeated without causing problems such as deterioration in battery performance. Specifically disclosed is a sodium ion secondary battery which is provided with a positive electrode, a negative electrode having a negative electrode active material, and a nonaqueous electrolyte solution containing a nonaqueous solvent. The nonaqueous solvent is substantially composed of a saturated cyclic carbonate (excluding the use of ethylene carbonate by itself), or a mixed solvent of a saturated cyclic carbonate and a chain carbonate, and a hard carbon is used as the negative electrode active material. It is preferable that the nonaqueous solvent used for the sodium-ion secondary battery is substantially composed of propylene carbonate, a mixed solvent of ethylene carbonate and diethyl carbonate, or a mixed solvent of ethylene carbonate and propylene carbonate.

An electrolyte for rechargeable batteries with a negative electrode of lithium or lithium containing alloys comprising: one or several non-aqueous organic solvents, one or several lithium salts and one or several additives increasing the cycle life of the lithium electrode. The electrolyte solution may comprise one or several solvents selected from the group comprising: tetrahydrofurane, 2-methyltetrahydrofurane, dimethylcarbonate, diethylcarbonate, ethylmethylcarbonate, methylpropylcarbonate, methylpropylpropyonate, ethylpropylpropyonate, methylacetate, ethylacetate, propylacetate, dimetoxyethane, 1,3-dioxalane, diglyme (2-methoxyethil ether), tetraglyme, ethylenecarbonate, propylencarbonate, γ-butyrolactone, and sulfolane. The electrolyte solution may further comprise at least one salt or several salts selected from the group consisting of lithium hexafluorophosphate (LiPF₆), lithium hexafluoroarsenate (LiAsF₆), lithium perchlorate (LiClO₄), lithium sulfonylimid trifluoromethane (LiN(CF₃SO₂)₂)) and lithium trifluorosulfonate (CF₃SO₃Li) or other lithium salts or salts of another alkali metal or a mixture thereof. Also disclosed is an electrochemical cell or battery with an anode of metallic lithium or a lithium-containing alloy, and such an electrolyte.

The invention relates to a synthesis technique of tenofovir, and relates to the field of medicinal chemistry. Using natural (R)-lactate as the starting material, chiral R-1,2-propanediol is obtained through reduction, and then reacted with diethyl carbonate under the action of alkali to obtain the key reaction intermediate R-propylene carbonate ester. Use adenine and R-propylene carbonate to prepare R-9-(2-hydroxypropyl)adenine; Gained R-9-(2-hydroxypropyl)adenine and diethyl p-toluenesulfonyloxyphosphate Under the catalysis of magnesium tert-butoxide, the condensation reaction is carried out to obtain R-9[(diethylphosphorylmethoxy)propyl]purine; the obtained R-9[2-(diethylphosphorylmethoxy) Propyl]purine is hydrolyzed to obtain Tenofovir. The process has short reaction steps, short required reaction time, high quality yield and good product quality, and is suitable for industrialized production.

A material (hereinafter referred to as “positive electrode material”) including sodium manganate powder as a positive electrode active material, carbon black powder as a conductive agent, and polytetrafluoroethylene as a binder is prepared. The positive electrode material is mixed in an N-methylpyrrolidone solution to produce slurry as a positive electrode mixture. A working electrode is produced by applying the slurry on a positive electrode collector. A negative electrode containing tin or germanium is produced. The non-aqueous electrolyte is produced by adding sodium hexafluorophosphate as an electrolyte salt in a non-aqueous solvent produced by mixing ethylenecarbonate and diethyl carbonate.

The invention belongs to a preparation method of a polymer lithium ion battery in the technical field of battery product development, which is characterized in that the polymer lithium ion battery comprises an anode system, a cathode system and gel polymer electrolyte, wherein, the anode system adopts lithium manganate and lithium nickelate cobaltate manganate in a weight ratio of 1:1-4, the cathode system adopts natural graphite and/or artificial graphite in a weight ratio of 0-100:100-0, the gel polymer electrolyte comprises a monomer/an initiator/organic electrolyte, the monomer is methyl acrylate/tetraethenol diacrylate, the initiator is a radical initiator, the organic electrolyte is ethylene carbonate/methyl ethyl carbonate/diethyl carbonate. The product prepared by the invention canmeet the requirements of the battery on capacity and overcharge protection, is excellent in high temperature storage and cyclicity and is widely applied to such electronic equipment as MP3, MP4, portable DVD and the like.

The invention provides a lithium-ion battery electrolyte, comprising a solvent and an additive, wherein the solvent comprises propyl propionate and two or three selected from a group consisting of vinyl carbonate, diethyl carbonate and propylene carbonate, and the additive comprises vinyl sulfate, fluoroethylene carbonate, adiponitrile, glycol bis(propionitrile) ether, 1,3-propanesultone and fluorobenzene. A lithium-ion battery prepared from the lithium-ion battery electrolyte has stable usability under the condition of 4.40 V or 4.45 V, has energy density of 750 Wh/L or above, cycle life of 800 times or above and a capacity retention ratio of 80% or above, so the service life of a novel high-voltage high-energy-density polymer lithium-ion battery is substantially improved.

The invention relates to a lithium iron phosphate battery with lithium ion battery electrolyte suitable for ultralow-temperature charging and discharging. The lithium ion battery electrolyte comprises lithium salt, a multi-element organic solvent and additives, wherein the additives comprise a low-melting-point additive, a film forming additive and a high-temperature additive; the multi-element organic solvent contains at least three of ethylene carbonate, diethyl carbonate, dimethyl carbonate, methyl ethyl carbonate, propylene carbonate and butylene carbonate; the low-melting-point additive contains at least one of 4-methyl-1,3-dioxolane, methyl acetate, methyl propionate, methyl butyrate, ethyl butyrate, propyl butyrate and butyl acetate; the high-temperature additive is at least one of methyl ester, di-n-propyl carbonate and 1,3-propane sultone. The lithium iron phosphate battery with the electrolyte can charge and discharge at an ultralow temperature and in a high-temperature environment, and is stable in performance and long in recycling life.

The invention discloses non-aqueous electrolyte for a lithium manganate power battery. The non-aqueous electrolyte comprises 70-90% of carbonic ester compound, 3-20% of various functional additives and 11-17% of lithium hexafluorophate, wherein the carbonic ester compound is one of or mixture of ethylene carbonate (EC), propylene carbonate (PC), butane carbonate (BC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl ethyl carbonate (EMC), methyl propyl carbonate (MPC) and methyl butyl carbonate (BMC); and the additives comprise 0.5-10% of a film forming additive, 0.5-10% of a high-temperature additive, 0.5-10% of an anti-overcharge additive, 0.5-10% of a flame retardant additive and 0.001-2% of a stability additive. In the non-aqueous electrolyte for the lithium manganate power battery of the invention, the performance of a solid phase interfacial film in the battery is improved, the compatibility of the electrolyte with negative electrode material is enhanced, and the cycle performance as well as the safety performance of the battery is greatly improved.

The invention belongs to the field of lithium batteries, in particular to a low-temperature lithium ion battery. The positive electrode sheet comprises a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer comprises 4.4 V lithium cobaltate material, a positive electrode conductive agent and a positive electrode binder. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer comprises a hard carbon coatedsecondary particle artificial graphite material, a negative electrode conductive agent, a dispersant and a negative electrode binder. The electrolyte comprises 10-20% of lithium hexafluorophosphate,10-20% of ethyl propionate, 10-20% of diethyl carbonate, 15-30% of vinyl carbonate, 15-30% of propyl propionate, 3-10% of fluorovinyl carbonate, 2-3% of propylene sulfite, 0.5-2.5% of ethylene glycolmonobutyl ether and 0.5-2.5% of 2, 2'-dithiopyridine. Compared with the batteries in the prior art, the lithium ion battery has good charging and discharging performance and higher energy density under low temperature condition.