12828results about How to "Improve cycle performance" patented technology

The negative electrode for a non-aqueous electrolyte secondary battery of the present invention includes a conductive porous substrate, and a conductive material and an active material filled in pores of the porous substrate. The active material contains at least one of a metal element and a semi-metal element capable of reversibly absorbing and desorbing lithium.

Silicon composite particles are prepared by sintering primary fine particles of silicon, silicon alloy or silicon oxide together with an organosilicon compound. Sintering of the organosilicon compound results in a silicon-base inorganic compound which serves as a binder. Each particle has the structure that silicon or silicon alloy fine particles are dispersed in the silicon-base inorganic compound binder, and voids are present within the particle.

This invention provides a film comprising a cross-linked polymer having an oxyalkylene group or a cross-linked polymer having an oxyalkylene group through a urethane bond, as a constituent component, a production method of the film, and an electrochemical apparatus using the film as a separator. The film for separator of an electrochemical apparatus can be easily and uniformly processed, can include an electrolytic solution, exhibits good film thickness and ensures excellent safety and reliability. The electrochemical apparatus is free of leakage of the solution.

To provide a working medium for heat cycle, of which combustibility is suppressed, which has less influence over the ozone layer, which has less influence over global warming and which provides a heat cycle system excellent in the cycle performance (capacity), and a heat cycle system, of which the safety is secured, and which is excellent in the cycle performance (capacity).

A working medium for heat cycle comprising 1,1,2-trifluoroethylene is employed for a heat cycle system (such as a Rankine cycle system, a heat pump cycle system, a refrigerating cycle system 10 or a heat transport system).

The invention provides a silicon-carbon composite anode material, which comprises a nuclear shell structure and a support substrate, wherein particle size of the silicon-carbon composite anode material is 1-200 micrometers, and porous carbon serving as the support substrate is obtained through decomposition of biomass materials. The invention further provides a preparing method of the silicon-carbon composite anode material, which includes the following steps: 1 reaming the biomass materials in physical activation or chemical activation mode to prepare the porous carbon, or preparing small molecular organics serving as a precursor of the porous carbon in hydrolyzing mode; 2 mixing silica particles and the obtained porous carbon or the precursor of the porous carbon in solution and performing ultrasonic treatment; 3 evaporating the solution mixture to dry so as to obtain solid-state powder; and 4 drying the solid-state powder, and performing thermal treatment, crushing and sieving on the solid-state powder to obtain the silicon-carbon composite anode material. The silicon-carbon composite anode material and the preparing method thereof are simple in process, short in flow path, easy to operate and low in cost, and lithium ion batteries manufactured by the silicon-carbon composite anode material are suitable for various mobile electronic equipment or devices driven by mobile energy.

The present invention relates to a preparation method for a nickel-manganese-cobalt anode material of a lithium ion battery. According to the present invention, in the presence of nitrogen atmosphere, a mixed solution containing nickel iron, manganese iron and cobalt ion reacts with a precipitating agent, then processes of aging, washing, drying and the like are performed to obtain a nickel-manganese-cobalt hydroxide precursor, the synthesized precursor material has spherical morphology, ideal particle size distribution and high tap density; the precursor, a lithium compound and a doped compound are mixed, then the sintering processing is performed for twice to prepare the nickel-manganese-cobalt three-element composite anode material. The method has characteristics of simple synthesis process, easy process controlling, low energy consumption, high efficiency and low cost, and is applicable for the industrial production; the prepared precursor material has characteristics of spherical morphology, uniform particle distribution and high tap density; the discharge capacity of the battery is improved through doping the metals; the cycle performance of the battery is stable.

Disclosed in the invention are a silicon-carbon composite anode material for lithium ion batteries and a preparation method thereof The material consists of a porous silicon substrate and a carbon coating layer. The preparation method of the material comprises preparing a porous silicon substrate and a carbon coating layer. The silicon-carbon composite anode material for lithium ion batteries has the advantages of high reversible capacity, good cycle performance and good rate performance. The material respectively shows reversible capacities of 1,556 mAh, 1,290 mAh, 877 mAh and 474 mAh/g at 0.2 C, 1 C, 4 C and 15 C rates; the specific capacity remains above 1,500 mAh after 40 cycles at the rate of 0.2 C and the reversible capacity retention rate is up to 90 percent.

The invention relates to a lithium ion battery silicon-based composite anode material, a preparation method of the lithium ion battery silicon-based composite anode material, and a battery. The lithium ion battery silicon-based composite anode material adopts an embedded composite core-shell structure, a core has a structure formed by embedding nano silicon particles into a gap of an inner layer of hollowed graphite, and a shell is made from a non-graphite carbon material. According to the silicon-based composite anode material, mechanical grinding, mechanical fusing, isotropic compression processing and carbon coating technologies are combined, so that the nano silicon particles can be successfully embedded into the inner layer of the graphite and the surfaces of graphite particles are uniformly coated; the high-performance silicon-based composite anode material is obtained and is excellent in cycle performance (the 300-times cycle capacity retention ratio is more than 90%) and high in first efficiency (more than 90%); in addition, the silicon-based composite anode material is high in specific energy and compaction density, and can meet the requirements of a high-power density lithium ion battery; the preparation process is simple, the raw material cost is low, and the environment is protected.

A method for making sulfur-graphene composite material is disclosed. In the method, a dispersed solution including a solvent and a plurality of graphene sheets dispersed in the solvent is provided. A sulfur-source chemical compound is dissolved into the dispersed solution to form a mixture. A reactant, according to the sulfur-source chemical compound, is introduced to the mixture. Elemental sulfur is produced on a surface of the plurality of graphene sheets due to a redox reaction between the sulfur-source chemical compound and the reactant, to achieve the sulfur-graphene composite material. The sulfur-graphene composite material is separated from the solvent.

A non-aqueous electrolyte secondary battery negative electrode material is provided wherein a negative electrode active material containing a lithium ion-occluding and releasing material which has been treated with an organosilicon base surface treating agent is surface coated with a conductive coating. Using the negative electrode material, a lithium ion secondary battery having a high capacity and improved cycle performance is obtainable.

The present invention is characterized by obtaining a high charge/discharge capacity upon high rate charging/discharging in a hybrid capacitor having characteristics of both an electric double layer capacitor and a lithium-ion secondary battery. Specifically, the present invention is a capacitor comprising: a positive electrode 1 composed of a polarizable electrode containing activated carbon; a negative electrode 2 containing as an anode active material a carbon material capable of inserting/extracting lithium ion; and a nonaqueous electrolyte containing lithium ion, wherein a charge cutoff potential for the negative electrode 2 is within the range of 0.15 to 0.25 V (vs. Li/Li⁺).

The invention discloses a lithium ion battery and a positive material, the positive material possesses a core-shell structure, the material of a core layer is at least one of lithium cobaltate, a ternary material and a lithium manganese material, the material of a shell layer is lithium nickel manganese spinel. The preparation method comprises the following steps: preparing the sol shell layer material, then adding the core layer material in the sol, stirring, drying and calcining to prepare the lithium ion battery positive material with the core-shell structure. In addition, the invention also discloses the lithium ion battery prepared by the positive material with the core-shell structure, the end of charge voltage is 4.3-4.7V(vs. Li), the lithium ion battery has excellent charge and discharge cycling performance and high temperature storage performance under high voltage.

The invention discloses a method for preparing silicon carbon cathode materials for lithium ion battery. The method includes synthesizing silicon oxide micro-spheres (SiOx micro-spheres), and then sequentially mixing, coating and carbonizing the SiOx micro-spheres and the pitch solution. The method for preparing silicon oxide (SiOx) / carbon (C) composite materials and the prepared silicon carbon cathode materials for lithium ion battery also disclose the silicon carbon cathode materials for lithium ion battery, the materials for lithium ion battery are prepared by mixing the SiOx micro-spheres/ C micro-spheres with artificial graphite. According to the method for preparing silicon oxide (SiOx) / carbon (C) composite materials, the rate of decay of the silicon carbon cathode materials is effectively prolonged, the circulation performance of the silicon carbon cathode materials is improved and the first circulation efficiency of the silicon carbon cathode materials is increased.

A negative electrode material for nonaqueous electrolyte secondary batteries comprises composite particles which are prepared by coating surfaces of particles having silicon nano-particles dispersed in silicon oxide with a carbon coating, and etching the coated particles in an acidic atmosphere. The silicon nano-particles have a size of 1-100 nm. The composite particles contain oxygen and silicon in a molar ratio: O<O/Si<1.0. Using the negative electrode material, a lithium ion secondary battery can be fabricated which features a high 1st cycle charge/discharge efficiency, a high capacity, and improved cycle performance.

PCT No. PCT/JP95/01897 Sec. 371 Date Mar. 19, 1997 Sec. 102(e) Date Mar. 19, 1997 PCT Filed Sep. 20, 1995A method of straightening a wire rod of titanium or titanium alloy wherein the rod is hot-straightened to a straight rod at the straightening temperature T and elongation epsilon satisfying the expression (1) or (2). The method includes hot rolling a titanium billet of beta titanium alloy, ( alpha + beta ) titanium alloy or a near alpha titanium alloy into a wire rod, winding the hot rolled wire rod into a coil, cold drawing the wire rod, cutting the wire rod to obtain a bent wire rod, heating the bent wire rod to a straightening temperature T while both end portions of the bent wire rod are fixed, applying a predetermined elongation epsilon to the wire rod, maintaining a straightening temperature T, hot-straightening the wire in accordance with the expression (2) epsilon (T-400)>/=400(1) epsilon (T-500)>/=200(2) and cooling the wire rod while applying tension. The method is suitable for preparing a straight rod for use in an engine valve.

The invention provides a high nickel anode material, which comprises a base body and a coating layer, wherein aluminum (Al), titanium (Ti), magnesium (Mg), zirconium (Zr), calcium (Ca), zinc (Zn), boron (B), fluorine (F), vanadium (V), strontium (Sr), barium (Ba), yttrium (Y), neodymium (Nd), caesium (Cs), tungsten (W), molybdenum (Mo), ruthenium (Ru), rubidium (Rb) or lanthanides are mingled on the surface of the base body, the coating layer is coated on the surface of the base body, and comprises one or more of the magnesium, the titanium, the zirconium, the fluorine, the boron, the aluminum and phosphate. The elements are mingled on the surface of the base body of the high nickel anode material, the mingled elements can stabilize a surface crystal structure of the base body, remit damage of washing liquid to a material surface structure of the base body, and enable capacity and cycle performance of a lithium ion battery which is prepared through the high nickel anode material to be better. Furthermore, the high nickel anode material is provided with the coating layer, and the coating layer enables the high nickel anode material to separate from an electrolyte part, and improves electrochemical stability and safety of the high nickel anode material. The invention further provides a method for preparing the high nickel anode material and a lithium ion battery.

A surface mount fuse includes a plurality of substrate/arc suppressive layers, a plurality of fusible elements positioned between the substrate/arc suppressive layers and terminations connected to the ends of the fusible elements, such that the fusible elements are electrically connected in parallel. The surface mount fuse has greater amperage and voltage ratings than similarly sized conventional surface mount fuses. Additionally, the surface mount fuse has increased interrupt breaking capacity and superior mechanical properties.

The invention has a grain structure with an outer shell and several inner cores. The grain size is from 100 nanometers to 100 microns. The inner cores are compound grain that includes active substance and conducting additive. The outer shell is a carbon layer. The active substance takes 20-95wt% of total cathode active material, and is mixture of one or several transition metallic compound selected from silicon and lithium storage whose thermodynamic equilibrium potential is less than 1.5v. The cathode material can be made by using mechanical process or thermal method, and can be directly used as cathode material or used with other existing cathode material.