204 results about "Silicon anode" patented technology

The present invention provides a composite silicon anode material hybridizing carbon nanofiber for lithium secondary battery prepared by the steps comprising: i) preparing a support made by amorphous silicon alloy after processing amorphous silicon and metal; ii) dispersing the catalyst selected from Fe, Co, Ni, Cu, Mg, Mn, Ti, Sn, Si, Zr, Zn, Ge, Pb or In on the surface of said support made by amorphous silicon alloy; and iii) growing the carbon nanofiber using a carbon source selected from carbon monoxide, methane, acetylene or ethylene on said support by a chemical vapor deposition method, wherein the amount of grown carbon nanofiber is 1˜110 wt % of the amount of said support.

Improved anodes and cells are provided, which enable fast charging rates with enhanced safety due to much reduced probability of metallization of lithium on the anode, preventing dendrite growth and related risks of fire or explosion. Anodes and/or electrolytes have buffering zones for partly reducing and gradually introducing lithium ions into the anode for lithiation, to prevent lithium ion accumulation at the anode electrolyte interface and consequent metallization and dendrite growth. Various anode active materials and combinations, modifications through nanoparticles and a range of coatings which implement the improved anodes are provided.

A method of forming a silicon anode material for rechargeable cells includes providing a metal matrix that includes no more than 30 wt % of silicon, including silicon structures dispersed therein. The metal matrix is at least partially etched to at least partially isolate the silicon structures.

The present disclosure relates to prelithiated Si electrodes, methods of prelithiating Si electrodes, and use of prelithiated electrodes in electrochemical devices are described. There are several characteristics of electrode prelithiation that enable the superior battery performance. First, a prelithiated silicon anode is already in its expanded state during SEI formation, and therefore less of the SEI layer breaks down and reforms during cycling. Second, the prelithiated anode has a lower anode potential, which may also help the cycle performance of an electrochemical device.

The invention discloses a preparation method of a silicon composite anode material provided with a gradient change coating layer on the surface, and aims to overcome conventional modification defects of a silicon anode material. According to the preparation method, a porous silicon material is prepared firstly, and on the basis, a chemical vapor deposition method is adopted to uniformly deposit a coating layer on the surface of the porous silicon material, wherein the coating layer adopts an elemental Si-SiC-C transition structure. A test is performed in a vapor deposition reacting furnace provide with segmented temperatures, independently controllable atmosphere and a plurality of furnace chambers. Compared with the prior art, a gradient change process is achieved through the surface coating layer, an obvious interface structure is not formed, the coating layer is tight, so that a volume effect and electric conductivity of the silicon-based anode material in a battery charge-discharge process are inhibited effectively, and the cycling stability of the material is improved greatly. The preparation method is simple in technology and suitable for large-scale industrial production, and has wide application prospect in the field of lithium ion batteries.

An anode active material comprising silicon particles with an interfacial layer formed on the surface of the silicon is provided. The interfacial layer has good electron conductivity, elasticity and adhesion among anode materials, thereby enhancing anode capacity and reducing stress caused by expansion of silicon particles during charge and discharge cycles. Direct contact between silicon particles and electrolyte is remarkably reduced as well. In addition, anodes and lithium batteries including the anode active material exhibit excellent capacity and cycle efficiency.

The present invention relates to a silicon anode active material capable of high capacity and high output, and a method for fabricating the same. A silicon anode active material according to an embodiment of the present invention includes a silicon core including silicon particles; and a double clamping layer having a silicon carbide layer on the silicon core and a silicon oxide layer between the silicon core and the silicon carbide layer.

The invention brings forward a novel low-cost in-situ solid-phase preparation method. By the method, a silicon-graphene spheroidal composite material with a multilevel structure can be synthesized by one step. The composite material can be used as a high specific energy anode material to be applied in a lithium ion battery. Low-cost organic carbohydrate and inorganic transition metal salt which are respectively used as a carbon source and a metal catalyst precursor are selected to be uniformly mixed with a silicon nano-material; by a tube furnace heating method, in-situ catalytic growth of a graphene coated network happens on the surface of silicon nano-particles; and through the bridging effect of the graphene network, spheroidal micro-scale particles with a nanometer fine structure is self-assembled. The silicon-graphene spheroidal composite anode material with the multilevel structure has an advantage of high specific capacity. In addition, two main bottleneck problems such as poor electronic conductivity of a silicon anode material and severe volume effect during the cyclic process can be overcome simultaneously, and multiplying power and cycle performance of silicon anode can be raised greatly.

The invention discloses a silicon-based composite anode material for a lithium ion battery and a preparation method thereof. The anode material comprises a graphite skeleton and an amorphous carbon layer which coats the graphite skeleton. The graphite skeleton is filled with a silicon material coated with a carbon-containing structure. The silicon material and the graphite skeleton are combined through a loose carbon material. The preparation method at least comprises the following steps: (1) preparing the silicon material coated with the carbon-containing structure; (2) preparing spherical particles with graphite as the main body; (3) coating the spherical particles with the amorphous carbon layer; and (4) granulating. According to the invention, the electric insulation problem of silicon anode due to its volume change can be solved, and it can be guaranteed that silicon active component can always be electrically contacted with a current collector during the charge-discharge cycle process. Meanwhile, huge stress effect caused by volume expansion/shrinkage of the active material silicon is further buffered. Then, the composite material has characteristics of high electrochemical cycle stability and regulable specific capacity.

The invention belongs to the technical field of preparation of lithium ion batteries, and particularly relates to a preparation method of a carbon nanotube composite porous silicon anode material for a lithium ion battery. The preparation method mainly comprises the following steps: preparing porous silicon by thermal reduction; coating the porous silicon with carbon by chemical vapor deposition and compounding carbon nanotubes; removing an iron catalyst by acid treatment. The preparation technology is low in energy consumption and cost, reversible capacity of the silicon anode material is increased effectively, the rate capability is improved, and the cycle life is prolonged. Primary particle sizes of the prepared porous silicon are 50-500 nm, a uniform carbon layer with the thickness range of 2-50 nm is deposited on the surface of the porous silicon, and the carbon nanotubes are distributed inside and outside particles, so that overall electronic conductivity of the porous silicon is improved.

The invention discloses a polymer crosslinked binder, a preparation method and application thereof. The polymer crosslinked binder is prepared by adopting double end group substituted polyethylene glycol as the crosslinking agent for crosslinking reaction with a water-soluble linear polymer binder. The invention verifies the feasibility of preparation of a three-dimensional polymer binder through crosslinking reaction. The polymer modified binder takes natural biologically modified macromolecule as the raw material, the sources are wide, the cost is low, and also the water solubility is good. The polymer reaction is carried out through Schiff base reaction, high temperature or a catalyst is unnecessary, and the implementation process is simple and feasible. Testing representation of the performance of a silicon anode prepared from the binder finds that crosslinking modification of the binder not only improves the binding performance of the binder, but also improves the ionic conductivity of the electrode, improves the electrochemical properties of the battery material, and enhances the battery comprehensive performance.

The invention aims at providing a lithium ion by a compensation lithium cathode to compensate the loss of battery cathode capacity by an alloy anode. The characteristic of a silicon anode causes the low efficiency for compensating lithium to the lithium ion battery in a system for the first time which has large loss to the cathode capacity. The advantage of high energy density of the silicon anode battery can be highlighted by using the lithium ion provided by the compensation lithium cathode to compensate the loss of battery cathode capacity. Through the method of compensating lithium, lithium can be respectively compensated for twice to a cathode pole and an anode pole, thereby the method is capable of raising the capacity and performance of the battery.

Embodiments of the claimed invention are directed to a device, comprising: an anode that includes a lithiated silicon-based material and a sulfur-based cathode, wherein the anode and the cathode are designed to have mesoporous structures. In certain embodiments, the sulfur-based cathode is a mesoporous carbon structure comprising sulfur within the mesopores. A further embodiment of the invention is directed to a device comprising a semi-liquid lithium-sulfur battery comprising a lithium anode and a sulfur cathode. In certain embodiments, the sulfur cathode comprises a liquid catholyte, which is housed within a reservoir that is a carbon nanotube sponge. An additional embodiment of the invention is directed to a method for producing a lithiated silicon anode and a sulfur-based cathode.

The invention discloses a lithium ion battery and relates to the technical field of batteries. The lithium ion battery prepared by using a binder provided by the invention can more firmly adhere a silicon negative material, a conductive agent and a current collector together during the charging and discharging process of the silicon anode, which can suppress the increase in internal resistance inthe battery cycle and improve the cycle performance of the battery. In addition, the fluorinated cyclic carbonate in the electrolyte can form a SEI film with good mechanical properties on the surfaceof the negative electrode, which can well adapt to the volume expansion-shrinkage change of the silicon negative electrode without being destroyed, and has a better effect than using alone in combination with the adhesive of the structural formula 1.

The application provides an electrode material preparation method, an electrode material and a battery, used to solve the problem existing in the prior art that the silicon anode material in the battery can be easily pulverized in a full-embedded state. The electrode material comprises: a layered silicon core and graphene quantum dots; wherein the layered silicon core comprises at least two layersof silicon based material; an interlayer gap between the adjacent two layers of the at least two layers of silicon based material; wherein the silicon based material comprises at least one of siliconor oxide of silicon; and wherein the graphene quantum dots are located in the interlayer gap of the at least two layers of silicon based material.

The present invention is based on an electrode binding material including polyacrylics and a functional group substituent(Li, Na, K) as a binder of an electrode. The present invention provides a polyacrylic acid an electrode binding material including a polyacrylics mixture having a high degree of polymerization and a functional group with Li, Na or K being substituted and high efficiency Lithium secondary battery utilizing a silicon anode active material etc. using the same. Therefore, the electrode binding material of the present invention has an excellent binding force, and can reduce side reactions in reactions of a secondary battery, and maintain a stable cycle property, and also enhance electric performance.

The invention relates to silicon-anode lithium battery electrolyte. The silicon-anode lithium battery electrolyte consists of an organic solvent, a lithium salt and additives, wherein the concentration of the lithium salt is 0.001-2 mol/L; the additives consist of an additive A and fluorinated ethylene carbonate; the mass of the additive A accounts for 0.1-20% of the mass of the electrolyte; the mass of the fluorinated ethylene carbonate accounts for 0.1-10% of the mass of the electrolyte; the additive A is a sulfite compound. In a silicon-anode lithium ion battery, in non-aqueous electrolyte, the sulfite compound and the FEC (fluorinated ethylene carbonate) are used, and in EC (ethylene carbonate)-based electrolyte, electrochemical improvement effect on a silicon anode is good, and a formed SEI (solid electrolyte interface) film is thicker, so that the defect that the silicon anode has large volume expansion change in the cycle is made up, the charge and discharge performance of the silicon-anode lithium ion battery can be improved more effectively, side reactions can be reduced, thereby reducing battery expansion and improving the cycle life of the battery, and thus the room temperature performance and the high temperature performance of the battery are very good.

The invention discloses a method of improving the performance of a lithium ion battery silicon anode material. The method comprises following steps: (1) preparing an anode material made of a silicon monoxide (SiO) composite material: (a) weighing a certain amount of SiO powder, pouring SiO powder into deionized water, wherein the mass ratio of SiO powder to deionized water is 1:10, and then addinga certain amount of graphite and glucose; (b) filling the obtained solution into a high energy ball milling machine, and carrying out ball milling; (c) after ball milling, placing the obtained precursor in a tubular furnace; and (d) mixing the prepared SiO/C composite material with a conductive agent (acetylene black) and an adhesive (PVDF) according to a certain ratio; and (2) carrying out a pre-lithiation treatment on an electrode. At first, a SiO material is compounded with a carbon material, then lithium is added into the composite material to carry out pre-lithiation modification, aftermodification, the modified SiO composite material is taken as a negative electrode, for the first time, the Coulomb efficiency is increased to 81% from 77%, and other performances of the SiO compositematerial are also greatly enhanced.

The invention relates to a pre-lithiatedanode material with the high reversible capacity and a preparation method of the pre-lithiatedanode material. The pre-lithiatedanode material comprises a graphite-like carbon material, metallic oxide or silicon uniformly distributed on the pre-lithiatedanode material, and lithium carbonate; the first coulomb efficiency of the anode material is 5%-10% higherthan that of the corresponding pure metallic oxide or silicon anode material, and the capacity retention rate of the anode material is no less than 85% after cycling for 100-350 times. The preparationmethod includes the steps that the metallic oxide or silicon powder, lithium carbonate powder, the graphite-like carbon material and a grinding agent are stirred,mixed and subjected to ball-milling.According to the pre-lithiatedanode material with the high reversible capacity and the preparation method of the pre-lithiatedanode material, by adding the lithium carbonate, the irreversible capacityof the anode material in the initial charging and discharging process is lowered, and thus the first coulomb efficiency is improved; by adding the graphite-like carbon material, structural stabilityof the material in the reaction process and conductivity of an electrode material are improved; and according to the ball-milling method, the size of the anode material particlescan be refined in a short time, and the volume change of the anode material is buffered.

Methods for making a negative electrode material for use in an electrochemical cell, like a lithium ion battery, are provided. The electroactive material includes a functionalized surface having a grafted reactive group (e.g., an amino group, a carboxyl group, an anhydride group, and the like). The electrically conductive material includes a functionalized surface having a grafted reactive group (e.g., an amino group, a carboxyl group, and the like). The functionalized electroactive material and the functionalized electrically conductive material is admixed and reacted with at least one binderprecursor having a reactive group (e.g., an amino group, an anhydride group, and the like). A porous solid electrode material is thus formed. Negative electrodes are also provided, which provide significant performance benefits and reduce the issues associated with capacity fade, diminished electrochemical cell performance, cracking, and short lifespan associated with conventional silicon anode materials.