2260 results about "Volume expansion" patented technology

An electrode according to the invention can provide a non-aqueous electrolyte secondary battery having an ability to release a volume expansion at the time of charge and discharge as well as the time of a cycle. The electrode comprises a current collector made of a material which is not alloyed with Li, and a dot pattern 2 of a metallic material able to be alloyed with Li formed on the current collector. At the time of charge, since the volume expansion of each dot 3 is carried out so as to bury adjoining crevices 4 between the dots, a stress generated is released, thereby degradation of an electrode being avoided. Each dot may also be made into porosity.

The invention discloses a preparation method of a composite lithium metal anode and belongs to the technical field of lithium metal batteries. The preparation method of the composite lithium metal anode comprises steps as follows: firstly, the surface of a framework material is modified, the framework material with the lithiophilic surface is prepared, the framework material is contacted with liquid metal lithium, so that the liquid metal lithium is injected into the framework material with the lithiophilic surface, and the composite lithium metal anode is prepared after cooling. The lithiophilic surface can be obtained through modification of various framework materials (including a conductive framework material and an insulated framework material), the framework materials are efficientlycomposited with the liquid metal lithium, and the composite lithium metal anode material is obtained. When the obtained composite lithium metal anode material is assembled in a total battery, growthof lithium dendrites can be effectively inhibited, the volume expansion effect of the anode is relieved, the pulverization phenomenon of the lithium metal anode is reduced, and the cycling stability and the safety of the lithium metal battery are substantially improved, and the cycle life of the lithium metal battery is substantially prolonged.

The invention relates to a preparation method of an emulsion deep profile/displacement control agent containing gel microspheres of a core shell structure. According to the method, materials are fed many times to carryout inverse emulsion low-temperature oxidation and reduction to initiate free radical polymerization so that water-solubility monomers (including acrylamide, ionic monomer I, the ionic monomer II and the third monomer) react with a cross-linking agent to generate the emulsion deep profile/displacement control agent containing gel microspheres of a core shell structure. The invention also relates to the emulsion deep profile/displacement control agent containing gel microspheres of a core shell structure, which is prepared by using the method. The profile/displacement control agent is a water-solubility microgel oil displacement material containing gel microspheres from nano scale to micron scale; with small initial grain size, the profile/displacement control agent can enter into the deep part of stratum; in addition, the profile/displacement control agent has high emulsion active component content and good flowability, can have volume expansion and mutual cementation under the actions of formation water and temperature according to the condition whether charges carried by the ionic monomers at a core layer and a shell layer are same or not; therefore the profile/displacement control requirements of different geological oil deposits of oil fields can be met.

The invention relates to a preparation method of a silicon/graphene nanocomposite material for a cathode of a lithium ion battery, which comprises the steps of: preparing oxidized graphite; preparing a silica/ graphene nanocomposite material under the existence of a surfactant; then preparing the silicon/graphene nanocomposite material for the cathode of the lithium ion battery through the magnesiothermic reduction reaction. Compared with the prior art, the graphene in the composite material, prepared by the invention, can better inhibit volumetric expansion of silicon material in the insertion and separation process of lithium ions so as to improve the circulating performance of the composite material greatly, so that the volume of the material after 30 circulations under the current of 200mA/g is still maintained to be above 1100mAh/g.

The invention discloses a lithium ion battery silicon-carbon composite negative material and its preparation method. A one-step coating granulation technology is adopted to disperse nanometer silicon powder in a three-dimensional conductive network formed by graphene in order to maintain close contact between the nanometer silicon powder and graphene, shorten the diffusion path of lithium ions and ensure no deprivation of electron conduction of the electrode material. Graphite with very high toughness can buffer the volume expansion of silicon in the charge and discharge process, and amorphous carbon formed through gas phase coating can maintain the stable structure of the material, so the lithium ion battery silicon-carbon composite negative material has excellent cycle performances and rate performances. The preparation method of the lithium ion battery silicon-carbon composite negative material has the advantages of simplicity, high efficiency, few steps and high yield, is suitable for large-scale industrial production.

A homogenizing fuel enhancement system involves at least one circulation loop existing outside of the injection system for continuously circulating and maintaining the homogeneity of a multi-fuel mixture apart from any demands by or delivery to the engine's injection system (whether mechanical injection or a common rail), and at least one infusion tube configured within the at least one circulation loop for providing a volumetric expansion wherein the fuel mixture is infused and thereby rendered more homogeneous.

An internal combustion engine of the present invention features separate compression and expansion cycles. The engine includes a separate compressor device which pressurizes air by a ratio greater than 15 to 1, at least one two stroke combustion cylinder and a compressed air conduit for transferring compressed air from the compressor to the at least one combustion cylinder. An air injection valve injects the compressed air into the combustion cylinder during the second half portion of the return stroke of the combustion cylinder. The compressed air is mixed with fuel and combusted for expansion during a power stroke. In this engine compression occurs only to a minor degree in the combustion cylinder. Accordingly, the compression ratio of the present engine may be significantly higher or lower than the volumetric expansion ratio of the combustion cylinder thus resulting in corresponding increases in either power density or thermodynamic efficiency respectively.

The invention discloses a spherical porous silicon/carbon composite material as well as a preparation method and application thereof. The spherical porous silicon/carbon composite material is structurally characterized in that a SiOx/C matrix, graphite with small particle size and a conductive agent are dispersed in porous amorphous carbon, wherein the average particle diameter is 12-25mu m; the method comprises the following steps of carrying out first coating on a SiOx raw material with powder pitch, and performing heat treatment so as to obtain a SiOx/C material; then performing ball milling by use of a wet method so as to reduce the particle diameter of powder, adding a carbon source adhesive, the graphite with the small particle diameter and the conductive agent, and performing high-speed dispersion, thereby obtaining pulp; and finally performing spray granulation and sintering on the pulp, thereby obtaining the final spherical porous silicon/carbon composite material. According to the invention, SiOx is dispersed in cracking carbon, the graphite and the conductive agent, so that SiOx volume expansion during a charge/discharge process is buffered, and the conductibility is enhanced; by virtue of the porous structure, the imbibition rate and cycle performance of the material can be effectively improved; by virtue of bitumencarb coating and high-heat treatment performed in advance, SiOx is prevented from being directly contacted with an electrolyte, and furthermore, the stability and first efficiency of the silicon/carbon material are improved.

Hydrogels are described which have delayed swelling properties. A hydrogel is formed by reacting a hydrophilic monomer, a first crosslinker, and a second crosslinker. The first crosslinker defines the volume expansion of the hydrogel in an aqueous environment, and the second crosslinker, which is biodegradable, can modulate the swelling rate of the hydrogel in aqueous solution. In its dry state, the hydrogel (xerogel) is flexible and elastic. It can also be cut with a knife or scissors, or molded or shaped by hand. The ready shapeability of the xerogel by trimming or compression affords a superior hydrogel for medical applications.

A loudspeaker system according to the present invention comprises a cabinet, a speaker unit mounted in the cabinet, and a powdery gas absorption material which is disposed in an internal space of the cabinet and physically absorbs gas being present in the internal space of the cabinet. An average particle diameter of the gas absorption material is less than 0.1 mm. Thus, according to the present invention, the loudspeaker system which expands a low frequency band, prevents a reduction in an acoustic pressure level, exhibits a volume expansion effect also in a high frequency band of 100 to 200 Hz or more, is compact, and enables enriched bass reproduction can be realized.

The invention discloses a silicon-carbon composite material, a preparation method of the silicon-carbon composite material, and a lithium ion battery containing the silicon-carbon composite material. The preparation method comprises the following steps of: (1) reducing silicon dioxide by using metal with activity larger than that of silicon, so as to obtain a porous silicon-metal oxide composite; (2) corroding the metal oxide by acid, so as to obtain porous silicon; and (3) coating the surface of the porous silicon by carbon by taking a carbon source as a raw material, so as to obtain the silicon-carbon composite material. The silicon in the silicon-carbon composite material is prepared through using a metallothermic reduction method and porous silicon particles prepared through using the metallothermic reduction method are micron-sized and hardly agglomerate; the pore walls and the pore diameters in the porous silicon particles are nano-sized; compared with imporous micron-sized silicon powder, for the silicon-carbon composite material, the porous silicon particles have the characteristics that a diffusion path of a lithium ion in a silicon substrate is shortened, thus being beneficial to charging and discharging with large current, the pores can hold the volume expansion of silicon during silicon intercalation and the charging and discharging cycle life of the material is prolonged. The surfaces of the porous silicon particles are coated with a carbon layer with the certain pores and the conductivity of the silicon-carbon composite material is enhanced.

Nanostructured anodes for high capacity rechargeable batteries are provided according to various aspects of the disclosure. The nanostructure anodes may comprise silicon nanoparticles for the active material of the anodes to increase the storage capacity of the batteries. The silicon nanoparticles are able to move relative to one another to accommodate volume expansion during lithium intercalation, and therefore mitigate active material degradation due to volume expansion. The anodes may also comprise elastomeric binders that bind the silicon nanoparticles together and prevent capacity loss due to separation and electrical isolation of the silicon nanoparticles.

The invention relates to a device for storing heat, comprising a heat storage medium which absorbs heat in order to store heat and releases heat in order to use the stored heat, and a container for holding the heat storage medium, the container being closed by a gastight cover, and the device comprising volume compensation means in order to compensate for a volume increase of the heat storage medium (3) due to a temperature rise and a volume decrease due to a temperature reduction. The invention furthermore relates to a method for storing heat, in which heat is transferred to a heat storage medium in order to store heat or heat is discharged from the heat storage medium to the heat carrier in order to use the heat, the heat storage medium being held in a container which is closed by a gastight cover, wherein a volume expansion of the heat storage medium (3) is compensated for by a volume increase of the container (1) or by heat storage medium (3) flowing out of the container (1) into a buffer container (21; 63, 65), and a volume decrease of the heat storage medium (3) is compensated for by a volume decrease of the container (1) or by heat storage medium (3) flowing out of the buffer container (21; 63, 65) into the container (1).

The invention discloses an MXene-based flexible composite negative electrode material and a preparation method thereof. According to the MXene-based flexible composite negative electrode material andthe preparation method thereof, a transition metal sulfide is loaded on a two-dimensional layered structure of the MXene material through a hydrothermal method. The agglomeration effect of the MXene material is overcome, and the collapse of a layered structure is prevented. Meanwhile, the energy density of the composite material is improved. The MXene material with high conductivity acts as a three-dimensional conductive network skeleton, so that the conductivity and the mechanical strength of the composite material are enhanced. The volume expansion of the transition metal polysulfide material in the charging process is buffered. Meanwhile, the material has good charge-discharge cycle stability. The composite material and expanded graphite are combined to prepare a self-supporting high-flexibility negative electrode material. In the charging and discharging process, the hydrophilic MXene material has high affinity to polysulfides. The electrochemical performance and the capacitive deionization performance of the composite negative electrode material can be further improved. Sulfides generated by transition metal sulfides are eliminated. The shuttle effect of the polysulfides is limited, and the service life of the negative electrode material is prolonged.

A subsea electrical power distribution system including a first chamber (20) housing a transformer, a second chamber (30) housing a power distribution system with busbars (32) for distribution of power to individual consumers connected to said busbars via connectors (33). The interface between the first and second chamber includes a flexible membrane (22) allowing the oil in the first chamber to expand into the second chamber and vice versa. The second chamber being connected to an external volume expansion chamber (34) allowing the pressure in the second chamber to balance against the pressure of the ambient sea.