382 results about "Cycle efficiency" patented technology

A nano graphene-enhanced particulate for use as a lithium-ion battery anode active material, wherein the particulate is formed of a single sheet of graphene or a plurality of graphene sheets and a plurality of fine anode active material particles with a size smaller than 10 μm. The graphene sheets and the particles are mutually bonded or agglomerated into the particulate with at least a graphene sheet embracing the anode active material particles. The amount of graphene is at least 0.01% by weight and the amount of the anode active material is at least 0.1% by weight, all based on the total weight of the particulate. A lithium-ion battery having an anode containing these graphene-enhanced particulates exhibits a stable charge and discharge cycling response, a high specific capacity per unit mass, a high first-cycle efficiency, a high capacity per electrode volume, and a long cycle life.

A heat pump cycle device includes a compressor for drawing and compressing refrigerant, a first high-pressure heat exchanger located for heating a first fluid circulating in a first fluid circuit using high-pressure refrigerant discharged from the compressor, a second high-pressure heat exchanger for heating a second fluid circulating in a second fluid circuit using the high-pressure refrigerant flowing out of the first high-pressure heat exchanger, a first heating heat exchanger located to heat a third fluid using the first fluid, a second heating heat exchanger located to heat the third fluid using the second fluid, a decompression unit located to decompress the high-pressure refrigerant flowing out of the second high-pressure heat exchanger, and a low-pressure heat exchanger for evaporating low-pressure refrigerant decompressed by the decompression unit. Because the first and second high-pressure heat exchangers are located, cycle efficiency can be improved.

The invention provides a silicon-carbon composite cathode material for preparing a lithium-ion battery at the room temperature and a preparation method thereof. The composite cathode material is a material with a nuclear shell structure and comprises the following proportional elements: 0.01-10% of simple substance silicon and 90-99.9% of carbon. With regard to the preparation method, silicon powder and graphite are mixed for ball grinding and then added with bitumen or polymer cladding material for ball grinding again, after the treatment of carbonization, the mixture is crushed and sieved to obtain the material containing 0.01-10wt% of silicon and 10-99.9% of carbon. The capacity of the material is more than 350mAh/g, the cycle efficiency of the material is larger than 90% for the first time, and keeps larger than 80% after 200 cycles, and the material has good charging and discharging property.

The present invention relates to a method for recycling LiFePO₄, which is an olivine-based cathode material for a lithium secondary battery. The present invention is characterized in that a cathode material including LiFePO₄ is synthesized using, as precursors, amorphous FePO₄.XH₂O and crystalline FePO₄.2H₂O (metastrengite) obtained by chemically treating LiFePO₄ as an olivine-based cathode material for a lithium secondary battery, which is produced from a waste battery. Since a cathode fabricated from the LiFePO₄ cathode material synthesized according to the present invention does not deteriorate the capacity, output characteristics, cycle efficiency and performance of the secondary battery and the cathode material of the lithium secondary battery may be recycled, the secondary battery is economically efficient.

The invention discloses a composite anode material LiFePO4-Li3V2(PO4)3/C for lithium ion batteries and a preparation method for the composite anode material, wherein, the LiFePO4 and the Li3V2(PO4)3 of the complex chemical compound LiFePO4-Li3V2(PO4)3/C are stoichiometrie compounds; the substance quantity ratio of the LiFePO4 and the Li3V2(PO4)3 is that LiFePO4/ Li3V2(PO4)3 is equal to an 1/x, and the x is more than zero and less than or equal to 1; the LiOH®qH2O, Li2CO3 or CH3COOLi®q2H2O is mixed uniformly with FePO4, 4H2O,V2O5, NH4H2PO4 and the polyethylene glycol to be blended to be the rheological phase after being added with water, and an obtained rheological phase precursor is roasted in the inert atmosphere for three to twenty hours under the temperature of 600-800 DEG C, which produces the composite anode material LiFePO4-Li3V2 (PO4)3/C for lithium ion batteries. The prepared composite anode material for lithium ion batteries has the advantages of large capacity, high efficiency of charge-discharge, good cycle efficiency, good high-rate performance, which is suitable for industrial production.

A gas turbine cycle that utilizes the vaporization of liquefied natural gas as a source of inlet air chilling for a gas turbine. The cycle uses regeneration for preheating of combustor air and offers the potential of gas turbine cycle efficiencies in excess of 60%. The systems and methods permit the vaporization of LNG using ambient air, with the resulting super cooled air being easier to compress and/or having fewer contaminants therein. As the air is easier to compress, less energy is needed to operate the compressor, thereby increasing the efficiency of the system. A portion of the vaporized natural gas may be used as the combustion fuel for the gas turbine system, thereby permitting multiple turbines to be operated using a single topping cycle. In alternative embodiments, the vaporization of the LNG may be used as part of a bottoming cycle to increase the efficiencies of the gas turbine system.

A highly supercharged gas-turbine generation system include a gas turbine power plant that is supercharged to a high inlet pressure, preferably over about 1.15 pressure ratio and preferably includes a transmission system with refrigerated transformers for increased output. The gas turbine power plant includes a precompressor that supercharges to a design pressure ratio of about 1.20 to 10, with a preferred pressure ratio of about 2. For high supercharging pressures, a pressure-reducer is located downstream of the gas turbine to maintain turbine outlet pressure that is close to the inlet pressure. The pressure-reducer is preferably an expander, but can alternatively be an orifice. A torque-limiting coupling on the shaft between the gas turbine and the generator prevents transient overload of the shaft. Capacity of the gas turbine plant is preferably controlled by varying supercharging pressure. The expander preferably has variable-pitch blades to allow efficient variation of turbine outlet pressure. For combined-cycle embodiments, a heat-recovery steam generator (HRSG) may be placed between the gas turbine and a downstream expander. For highest combined cycle output, a single-pressure steam system with high inlet temperature to the HRSG is preferred. The high temperature is preferably provided by supplemental firing between the gas turbine and the HRSG. An expander may be inserted between the supplemental firing and the HRSG to further improve cycle efficiency and to reduce pressure in the HRSG. For retrofit applications with limited supercharging, a refrigeration system for generator cooling may be added to increase generator output to match that available from the supercharged gas turbine.

Disclosed is an electrolytic solution including an organic solvent, a lithium salt, and an additive. The additive includes maleimide compound and vinylene carbonate. The maleimide compound can be maleimide, bismaleimide, polymaleimide, polybismaleimide, maleimide-bismaleimide copolymer, or combinations thereof. The lithium battery employing the described electrolytic solution has a higher capacity of confirmation, higher cycle efficiency, and longer operational lifespan.

The invention relates to a method for applying ferro phosphorus to manufacture electrode material with low cost, belonging to a material and electrochemical field. The ferro phosphorus at least comprises P and Fe elements at the same time, thus providing part or all sources of phosphorus and ferro for the electrode material; the ferro phosphorus can be mineral, the smelt products thereof, byproducts of phosphorus chemical industry or silicate chemical industry, or self-made. Compared with the prior art, the method has rich source, low cost, simple manufacture method and process, short production flow; the impurity elements inside the material can be used for carrying out in-situ self-doping modification the invention can effectively increase cycling efficiency and utilization rate of resources, and reduce electrode material cost from the source; the invention is practical and easy for large-scale industrial clean production to realize consumption reduction, energy conservation and comprehensive utilization of resources.

The invention discloses a preparation method of an aluminum oxide-coated positive electrode material for a lithium-ion battery. The method comprises the following steps of (1) adding water to a hydroxide precursor of a positive electrode material for stirring to obtain positive electrode material precursor slurry; (2) dissolving sodium metaaluminate into water to obtain an aluminum salt solution; (3) adding the aluminum salt solution to the positive electrode material precursor slurry, stirring and introducing CO2 to obtain an aluminum hydroxide-coated positive electrode material precursor; (4) filtering, washing and drying slurry of the aluminum hydroxide-coated positive electrode material precursor to obtain aluminum hydroxide-coated positive electrode material precursor powder; (5) mixing the aluminum hydroxide-coated positive electrode material precursor powder with a lithium salt to obtain mixed powder; and (6) carrying out thermal treatment on the mixed powder to obtain the aluminum oxide-coated positive electrode material for the lithium-ion battery. The method is carried out in a water solution, an organic solvent is not used, and the discharge capacity and the cycle efficiency of the lithium-ion battery are improved through the method.

It is an object of the present invention to reduce the constraint that the density ratio is constant as small as possible, and to obtain high power recovering effect in a wide operation range by using an expander which is operated in accordance with a flowing direction of refrigerant. A determining method of a high pressure of a refrigeration cycle apparatus in which a refrigeration cycle uses carbon dioxide as refrigerant and has a compressor, an outdoor heat exchanger, an expander and an indoor heat exchanger, and the refrigeration cycle including a bypass circuit provided in parallel to said expander, and a control valve which adjusts a flow rate of refrigerant flowing through said bypass circuit, said compressor being driven by power recover by said expander, wherein if an optimal high pressure of a first refrigeration cycle flowing through said expander and a second refrigeration cycle flowing through said bypass circuit is defined as Ph, and a bypass amount ratio flowing through said bypass circuit in said Ph is defined as Rb0, and a maximum refrigeration cycle efficiency of said first refrigeration cycle in said Ph is defined as COPe, and a maximum refrigeration cycle efficiency of said second refrigeration cycle in said Ph is defined as COPb, the optimal high pressure Ph which maximizes (1-Rb0)xCOPe+Rb0xCOPb is determined.

The invention provides a modified nickel, cobalt and lithium manganite three-element material and a titanium dioxide layer compounded on the surface of the nickel, cobalt and lithium manganite three-element material. The titanium dioxide layer is creatively compounded on the surface of the nickel, cobalt and lithium manganite three-element material, the surface microstructure change of the NCM three-element material in the first-time charging process is effectively decreased, and the first-cycle efficiency is improved. In addition, due to the fact that titanium dioxide serves as a shell layer and form a core-shell structure with the NCM material, only lithium ions can pass through the titanium dioxide layer, and nickel and manganese ions cannot pass through, dissolution of Ni and Mn in the three-element material in the cycling process is reduced, and the cycle performance of the three-element material is optimized.

A system and method for supercharging a combined cycle system includes a forced draft fan providing a variable air flow. At least a first portion of the air flow is directed to a compressor and a second portion of the airflow is diverted to a heat recovery steam generator. A control system controls the airflows provided to the compressor and the heat recovery steam generator. The system allows a combined cycle system to be operated at a desired operating state, balancing cycle efficiency and component life, by controlling the flow of air from the forced draft fan to the compressor and the heat recovery steam generator.

The invention discloses a coal-fired power generation and waste heat power generation coupling system for a private station of a cement kiln, comprising a coal-fired boiler, a kiln head waste heat boiler, a kiln tail waste heat boiler, a kiln head steam pocket, a kiln tail steam pocket, a condensing steam turbine, a condensate pump, a heater, a deaerator, a water feeding pump and related auxiliary devices, wherein the kiln head waste heat boiler utilizes a dual-pressure system; a primary economizer of the low-pressure system is used as a public economizer for the waste heat power generation; the high-pressure steam and the steam generated by the kiln tail waste heat boiler are collected to the main steam pipeline of the waste heat power generation system; one path of the main steam pipeline is connected with a steam turbine of the waste heat power generation system while the other path thereof is connected with non-adjustable extraction steam of a coal-fired steam turbine; one path ofthe main steam pipeline of the coal-fired unit is connected with the coal-fired steam turbine while the other path thereof is connected with the waste heat steam turbine. In the invention, the coal-fired power generation is rationally coupled with waste heat power generation system so that the problem that the stability of the waste heat power generation system of the cement kiln is low is solved, and the whole thermal circulating efficiency of the private station can be largely increased.

There are disclosed electrolytes comprising solutions of lithium salts with large anions in polar aprotic solvents with a particular concentration of background salts. The concentration of the background salts is selected to be equal or close to the concentration of a saturated solution of these salts in the aprotic solvents used. The electrolytes disclosed can be used in chemical sources of electric energy such as secondary (rechargeable) cells and batteries comprising sulphur-based positive active materials. The use of such electrolytes increases cycling efficiency and cycle life of the cells and batteries.

The invention provides a high-security metallic lithium cathode and a preparation method thereof. The high-safety metallic lithium cathode comprises a lithium powder porous electrode and a silicon-based protecting layer, wherein the silicon-based protecting layer is arranged on the lithium powder porous electrode in an evaporation manner; the silicon-based protecting layer is 0.02-0.2 micrometers thick. Through the adoption of the technical scheme, the silicon-based protecting film with a lithium storage function is arranged on the metal lithium powder electrode in the evaporation manner, so that the security of the metallic lithium cathode is greatly improved; the high-security metallic lithium has relatively high current density and relatively small inner resistance; meanwhile, the cycle efficiency is improved, and a development space is provided for application of the metallic lithium cathode in the field of high-energy batteries.

A novel power generation system, more specifically an integrated power generation and air separation system and an integrated power generation and air separation process is provided. A key component of the system and process is an oxygen-fired combustor designed for gas turbine operating pressures. The combustor produces a high-temperature gas stream that enters one or more heat exchangers to generate/heat steam, and then enters one or more turbines to generate power. The steam from the heat exchanger drives one or more steam turbines to generate power, and the discharged steam is admitted to the combustor. To maximize cycle efficiency, steam extraction and reheat is incorporated in the process. Additional power is generated from a high-pressure nitrogen stream produced by an air separation unit (ASU). This process has the potential to attain high cycle efficiencies with zero emissions, while utilizing existing or near-term steam turbines, and moderate-pressure combustion systems.

The invention provides a method for preventing and treating regional farmland non-point source pollution through a farmland ditch and pond system. According to the method for preventing and treating the regional farmland non-point source pollution through the farmland ditch and pond system, an ecological pond is added to a farmland irrigation and drainage ditch based on arrangement and improvement of the farmland irrigation and drainage ditch according to a farmland surface runoff confluence track, the water flow speed of the farmland ditch is rapidly slowed down, the buffering capacity of a farmland system against water is reinforced, the cycle efficiency of farmland interior water sources and nitrogen and phosphorus nutrients is improved, the farmland non-point source sewage discharge is reduced, farmland nitrogen and phosphorus pollutant discharge is effectively cut down, and the method plays a greater role in protecting regional water environment.

The invention relates to a method for recycling alumina and sodium oxide from bayer process red mud. In the method, by adopting a high molecular ratio and high alkali concentration sodium aluminate solution, aluminum extracting reaction can be rapidly carried out under mild operating conditions, so that the recovery rate of alumina in the red mud reaches more than 85%, and the defects, such as equipment scabbing and the like can be effectively prevented and even eliminated; by implementing an efficient crystallization process of an intermediate product of hydrated sodium aluminate, the cycle efficiency of a dissolution medium is greatly improved; due to complete transformation of a phase in the aluminum extracting reaction, a reaction process of recycling sodium oxide can be performed at low temperature and normal pressure; and after secondary sodium removal reaction, the sodium oxide content in final red mud is not more than 1% and is far less than 6-8% of the bayer process red mud. Therefore, the red mud can be doped in large proportion for preparing cement, brick and roadbed materials, concrete additives, environmental remediation materials and other fillers, and the problems such as resource utilization of the red mud, potential environment hazard and the like are hopefully solved.