61results about How to "Electrochemical stability" patented technology

Nonaqueous electrolytic liquids for lithium secondary batteries which have flame retardancy (self-extinguishing characteristics) or incombustibility (no flash point), have a high conductivity, and are electrochemically stable. One of the nonaqueous electrolytic liquids comprises a nonaqueous solvent comprising as an essential ingredient at least one phosphate (a) selected among chain phosphoric esters (a1) and cyclic phosphoric esters (a2). The nonaqueous solvent may further contain a cyclic carboxylic ester (b1) and a cyclic carbonic ester (b2). Another nonaqueous electrolytic liquid comprises the nonaqueous solvent and incorporated therein at least either a vinylene carbonate compound (c1) or a vinylethylene carbonate compound (c2) and one or more compounds selected from the group consisting of cyclic amide compounds (d1), cyclic carbamate compounds (d2), and cyclic hetero-compounds (d3).

A polymeric electrolyte and a lithium battery lithium employing the same. The polymeric electrolyte includes a cross-linked polyether urethane prepared by reacting a pre-polymer having a polyethylene oxide backbone and terminated with NCO, with a cross-linking agent, organic solvent and lithium salt. Since the polymeric electrolyte is electrochemically stable, a lithium battery having improved reliability and safety can be obtained by employing the polymeric electrolyte.

In a state where a silicon base material (1) is used as an anode, a fine platinum member (2) is used as a cathode, and an electrolyte solution (4) is arranged between the anode and the cathode, anodicoxidation is performed in constant current mode under the conditions where porous formation mode and electrolytic polishing mode coexist. The platinum member (2) is fitted in the silicon base material (1) with silicon elution, and processes such as hole making, cutting, single-side pressing are performed. Since the silicon base material can be processed at a room temperature with small energy, the crystal quality of the processing surface is not deteriorated. Thus, efficient and highly accurate processing can be performed without using a mechanical method, which consumes much material in conventional processes such as cutting of solar cell silicon base material, and without using laser whose energy unit cost is high, and furthermore, without leaving a crystal damage on a processed surface.

The object of the invention is an electrode for a Li-ion battery, which contains a crosslinked polyether-siloxane copolymer (V), which can be prepared by crosslinking of siloxane macromers (S) having the average general formula (1): HaR1bSiO(4-a-b) / 2 (1), where R1 is a monovalent, SiC-bonded C1-C18 hydrocarbon radical which is free of aliphatic carbon-carbon multiple bonds and a and b are nonnegative integers, with the proviso that 0.5<(a+b)<3.0 and 0<a<2, and that at least two silicon-bonded hydrogen atoms are present per molecule, by means of polyether macromers (P) containing at least two alkenyl groups per molecule and optionally further compounds (W) containing alkenyl groups, with polyethylene glycols functionalized by one allyl group being excepted from the compounds (W) as binder; and also a process for preparing a crosslinked polyether-siloxane copolymer (V) as binder for the electrode in a Li-ion battery in a crosslinking step.

Disclosed is a porous membrane used for a secondary battery, such as lithium-ion secondary battery, wherein strength is improved and break is difficult to occur while maintaining lithium-ion conductivity. The porous membrane for a secondary battery comprising a binder for the porous membrane and a nonconductive particle, wherein the binder for the porous membrane is a polymer particle having a hetero phase structure, in which internal layer is a polymer wherein vinyl monomer components are polymerized and outer layer is a polymer wherein monomer components containing a hydrophilic functional group are polymerized. The hydrophilic functional group is at least one selected from the group consisting sulfonic acid group, carboxyl group, hydroxyl group and epoxy group.

The present invention discloses cross-linked polymethacrylic ethylene carbonic acid ester polymer electrolyte membrane and the preparation method. The polymer electrolyte membrane consists of cross-linked polymethacrylic ethylene carbonic acid ester polymer and electrolyte solution including conductive lithium salt and non-protonic solvent. The preparation method adopts carbon dioxide, epoxy dimethylmethane and unsaturated acid anhydride which are synthesized into polymethacrylic ethylene carbonic acid ester trivalent copolymer with special functional group under the role of catalyst dyadic carboxylic acid zinc. Then the trivalent copolymer is under the cross-linking reaction so as to get the dry polymethacrylic ethylene carbonic acid ester polymer membrane. Afterwards, the dry membrane is immerged into the liquid electrolyte solution for activation, thus obtaining the cross-linked polymethacrylic ethylene carbonic acid ester polymer electrolyte membrane. The polymer electrolyte membrane prepared by the present invention has the advantages of high mechanical performance, good thermal performance and high ion electric conduction. The present invention with low cost and simple process is applicable to the industrialized production.

The invention discloses an electrolyte solution and a lithium-ion secondary battery. The electrolyte solution comprises an aprotic organic solvent, electrolyte lithium salt and an additive, wherein the additive is cyclic phosphoric anhydride; and the mass of the additive accounts for 0.01-10 percent of the total mass of the electrolyte solution. The lithium-ion secondary battery comprising the electrolyte solution can be subjected to electrochemical oxidation polymerization under the voltage of over 4.4V (vs.Li / Li+). By forming a polymer on the surface of a positive pole material, a good barrier is formed to cover strongly-oxidative active points of the positive pole material, and decomposition of a main solvent of the lithium-ion secondary battery is inhibited, so that the stability of the electrolyte solution under a high-voltage state and the high-voltage cycle and storage performances of a lithium-ion battery are improved.