424 results about "Boron doping" patented technology

The invention relates to a preparation method of a solar cell piece and the solar cell piece, and the preparation method of the solar cell piece comprises the following steps: preparing a tunneling oxide layer on the surface of an n-type crystalline silicon substrate, depositing polycrystalline silicon on the surface of the tunneling oxide layer under a first condition, and forming a first polycrystalline silicon layer, polycrystalline silicon is deposited on the surface of the first polycrystalline silicon layer under a second condition to form a second polycrystalline silicon layer, the temperature T1 of the first condition is larger than the temperature T2 of the second condition, the crystallization rate in the first polycrystalline silicon layer is smaller than the crystallization rate in the second polycrystalline silicon layer, annealing treatment and boron diffusion are carried out on the first polycrystalline silicon layer and the second polycrystalline silicon layer under the same condition, and the polycrystalline silicon layer is formed. The first polycrystalline silicon layer is converted into a first doped polycrystalline silicon layer, the second polycrystalline silicon layer is converted into a second doped polycrystalline silicon layer, the ratio F of the concentration of the first doped polycrystalline silicon layer to the concentration of the second doped polycrystalline silicon layer is larger than or equal to 0.01 and smaller than or equal to 0.1, the boron doping concentration in the first doped polycrystalline silicon layer in direct contact with the tunneling oxide layer is reduced, and the passivation level is improved.

The invention belongs to the technical field of back contact photovoltaic cells, and particularly relates to a back contact photovoltaic cell with high-concentration co-doped regions and a manufacturing method and application thereof.The back contact photovoltaic cell with the high-concentration co-doped regions is characterized in that N-type doped regions and P-type doped regions which are alternately distributed are arranged on the backlight face of an intrinsic amorphous silicon layer, and the high-concentration co-doped regions are arranged between the N-type doped regions and the P-type doped regions; a doping source of the co-doped region comprises doping source phosphorus of the N-type doped region and doping source boron of the P-type doped region, the co-doped region, the doping source of the N-type doped region and the doping source of the P-type doped region form a specific concentration gradient structure, and the specific concentration gradient structure meets the condition that the doping concentration of phosphorus contained in the co-doped region is greater than that of phosphorus contained in the N-type doped region; the doping concentration of boron contained in the co-doped region is greater than the doping concentration of boron in the P-type doped region. The carrier transport and collection efficiency is optimized, the fill factor and open-circuit voltage are improved, the cell conversion efficiency and stability are improved, the preparation process is simple, and multiple times of opening etching are not needed.

The invention discloses a method and device for removing polyfluorinated perfluorides in a water body, and the method comprises the following steps: 1, pretreatment: removing large-particle impurities in the water body to be treated through a grid, then feeding the water body to be treated into a pH adjusting tank, and adding an acidic mixed solution to reduce the pH value to 4.0; 2, electrochemical oxidation: enabling the water body to flow into an electrochemical oxidation module, and reacting for 20-40 minutes under the voltage of 10V; when the method is implemented, long-chain PFAS is decomposed into short-chain products through three-stage cooperation of electrochemical oxidation, adsorption enrichment and membrane separation, so that subsequent removal of the short-chain PFAS is facilitated, the removal rate can be improved, the whole process is simpler compared with the prior art, and a large amount of cost is saved; the boron-doped diamond anode and the iron-cobalt bimetallic cathode are combined, and the modified biochar adsorbent is combined, so that the PFAS degradation rate is increased, and meanwhile, the electrode loss can be reduced.

The invention discloses a diamond piezoresistive material and pressure sensing application thereof, and particularly relates to a boron-doped diamond-based piezoresistive material and an application method thereof in a sensor, a gradient doping structure and heterogeneous layer design are adopted, and the diamond piezoresistive material with high sensitivity, high linearity, temperature stability, corrosion resistance and radiation resistance is constructed; by optimizing a CVD process and a pattern etching structure, stable piezoresistive response in an environment of-60 DEG C to 250 DEG C is realized, the cycle life exceeds 10 times, and the high-reliability piezoresistive sensor is suitable for high-reliability sensing devices under extreme working conditions such as aerospace engines, deep sea detection equipment and nuclear reactors.

The embodiment of the invention relates to the photovoltaic field, and provides a back contact cell and a processing method thereof, a back contact laminated cell and a photovoltaic module, and the processing method comprises the step of texturing a substrate. And carrying out boron diffusion on the substrate to form a boron-doped layer and a borosilicate glass layer on the surface of the substrate. And performing laser etching on the first region and the second region of the substrate, and removing the boron-doped layer, the borosilicate glass layer and part of the substrate in the first region and the second region. And carrying out phosphorus expansion on the substrate, and forming a polycrystalline silicon layer and a phosphorosilicate glass layer on the surface of the substrate. And performing laser etching on the substrate to remove the phosphorosilicate glass layers in the second area and the third area. And texturing the substrate and removing the phosphorosilicate glass layer in the first region and the polycrystalline silicon layers in the second region and the third region to form a textured surface in the second region. And forming a passivation layer on the substrate. Electrode paste is printed in the first area and the third area and sintered. And sintering the back surface of the substrate. The design can improve the double-sided rate and the efficiency of the back contact battery.

The invention discloses a silicon-carbon material as well as a preparation method and application thereof. The silicon-carbon material comprises nitrogen-doped porous carbon and an amorphous carbon layer coating the nitrogen-doped porous carbon, and pores of the nitrogen-doped porous carbon are filled with boron-doped nano silicon. The nitrogen-doped porous carbon improves the affinity of silane gas while improving the electron conductivity, a high-conductivity and high-density silicon-carbon composite structure is realized, the boron-doped nano silicon and the nitrogen-doped porous carbon form a nano heterojunction site, and the migration rate of lithium ions is improved, so that electrochemical reaction kinetics is improved, and the electrochemical performance of the lithium ion battery is improved. The material has the advantages of high rate and long cycle performance.

The invention relates to the technical field of solar cells, and particularly discloses a high-boron-doped single-mask TBC solar cell structure and a manufacturing method thereof.In the process of forming a patterned region, a P region does not need a mask structure, and through the combination of boron diffusion doping, annealing and two-time laser doping treatment, the high-boron-doped single-mask TBC solar cell structure is obtained. The boron atom doping concentration of the polycrystalline silicon layer is greatly improved, so that the boron-doped polycrystalline silicon layer in the P region is high in doping concentration and uniform in doping. According to the TBC solar cell prepared by the method, the processes of preparing and removing the mask structure are simplified, the technological process is short, the manufacturing cost is low, the contact resistance is reduced, the passivation effect is improved, the filling factor of the cell is increased, and the efficiency of the cell is improved. And the open-circuit voltage and the photoelectric conversion efficiency of the battery are improved.

The invention relates to the technical field of composite catalyst materials, in particular to a ferrocobalt bimetal hydroxide / BCN composite material and a preparation method and application thereof.The preparation method comprises the steps that cobalt nitrate and ferric nitrate are used for preparing a metal salt solution, sodium carbonate and sodium hydroxide are used for preparing a precipitant solution, a B-doped carbon nitride BCN material is added into the metal salt solution to form a uniform suspension, and the suspension is dried to obtain the ferrocobalt bimetal hydroxide / BCN composite material; dropwise adding the precipitant solution into the suspension to obtain a precursor solution, performing hydrothermal reaction on the precursor solution, and performing centrifugal impurity removal and drying to construct a heterostructure between layered double hydroxide and BCN in situ to obtain the Co-Fe LDH-coated BCN composite material. Through boron doping and heterostructure construction, the charge separation capacity of graphite carbon nitride is enhanced, the electron migration efficiency is improved through a heterointerface structure, the metal ion release amount and the cycle stability are controlled, and the catalytic performance is remarkably improved.

The invention relates to the technical field of semiconductor etching materials, and provides a method for preparing a high-resistivity silicon carbide material and the silicon carbide material. The method comprises the following steps that a substrate is placed in chemical vapor deposition equipment, the chemical vapor deposition equipment is vacuumized, and then inert gas is introduced; silicon carbon source gas and carrier gas are injected into the chemical vapor deposition equipment through a first gas inlet channel, boron source gas is injected into the chemical vapor deposition equipment through a second gas inlet channel, and silicon carbide is deposited on the surface of the substrate through a chemical vapor deposition process; after gradient annealing is carried out, the substrate is removed; wherein in the step 2, the distance between the air inlet of the first air inlet channel and the air inlet of the second air inlet channel is larger than or equal to 20 cm. According to the method, the doping amount of boron in silicon carbide can be obviously improved, so that the resistivity of silicon carbide is improved, and the etching resistance of silicon carbide is improved.

The invention discloses a diamond MOSFET device compatible with a CMOS ohmic contact process and a preparation method of the diamond MOSFET device. The preparation method comprises the steps that S1, a diamond substrate is selected, and an intrinsic diamond layer is grown on the diamond substrate in a homoepitaxial mode; s2, preparing a mask, and forming a boron-doped diamond layer in a source region and a drain region on the intrinsic diamond layer through boron ion implantation; s3, depositing a layer of Si film and a layer of Ti film on the surface of the sample; s4, performing two-step annealing on the sample to obtain ohmic contact formed by the boron-doped diamond layer, the boron-doped silicon layer and the titanium silicide layer; s5, removing the mask and the thin film above the mask; s6, preparing a terminal diamond surface layer; s7, preparing a passivation layer and windowing to form a source window and a drain window; and S8, preparing a gate electrode. According to the method, high-quality ohmic contact can be formed on the diamond through the gold-free process, the gold ion pollution risk is thoroughly avoided, and CMOS process compatibility is achieved.

Techniques are provided to form an integrated circuit having different semiconductor devices with different backside contact structures. Field effect transistors (FETs) each includes semiconductor material extending in a first direction between source and drain regions, and gate structures extending in a second direction around the semiconductor material of each FET. Different contact structures are formed on the source or drain regions of the n-channel FETs compared to the p-channel FETs. A backside contact structure on an n-channel source or drain region includes a first layer of phosphorous-doped titanium, a second layer that includes scandium, and a third layer that includes a metal, such as molybdenum. A backside contact structure on a p-channel source or drain region may include only a layer of metal, such as molybdenum, or the layer of metal and a layer of boron-doped titanium. The contact structures may be used to provide enhanced ohmic contact.

The invention relates to the technical field of solar cells, and particularly discloses a TOPCon cell with a domain surface structure and a preparation method of the TOPCon cell. The TOPCon battery comprises an N-type silicon substrate, the front surface of the N-type silicon substrate is divided into an emitter region and a non-emitter region, the emitter region is of a planar structure, the non-emitter region is of a pyramid textured structure, and the boron doping concentration of the emitter region is higher than that of the non-emitter region. According to the invention, the silicon oxide layer is generated in the emitter region through the laser oxidation process, so that local planarization is realized; in combination with selective boron diffusion doping, the contradiction between the contact resistance and the light absorption efficiency of the traditional TOPCon cell is solved; the specific process comprises the steps of alkali polishing, laser oxidation, texturing, doping, passivation, electrode printing and the like. And the process is stable, is compatible with the existing production line, and has remarkable industrial application value.

The invention relates to the technical field of electrode paste, in particular to electrode paste for a submerged arc furnace and a preparation method of the electrode paste. Comprising three-level grain size distribution anthracite aggregate which is electrically calcined at high temperature and modified by a KH-550 silane coupling agent, a modified silicon carbide whisker and boron-doped graphene-like carbon nitride composite filler, a maleic anhydride-mediated compatible medium-temperature pitch-polyborosiloxane binder and a graphite powder-borax functional additive. A step-by-step mixing and two-stage sintering process is adopted in the preparation process, a covalent bond interface bridging structure is constructed through the coupling agent, the composite dispersing agent regulates and controls the multi-dimensional network distribution of the filler, and the process synergistically improves the compactness and the interface bonding force of the green body. The electrode paste is firm in interface bonding, can form a ceramic protective phase at a high temperature, has excellent conductivity and mechanical strength, and prolongs the service life of the electrode paste for the submerged arc furnace.

A method and an apparatus for conformal boron doping of a three-dimensional structure. The method comprises: removing an oxide layer from a surface of a silicon-based three-dimensional (3D) substrate; forming, after removing the oxide layer, a first group of stacked films on a surface of the silicon-based three-dimensional substrate; forming a second group of stacked films on a surface of the first group of stacked films away from the silicon-based 3D substrate; depositing an aluminum oxide passivation layer on a surface of the second group of stacked films away from the first group of stacked films; and boron-doping the silicon-based 3D substrate through laser annealing or rapid thermal annealing, where the laser annealing or the rapid thermal annealing drives boron dopants, which comprises boron oxide, into the silicon-based 3D substrate via an auxiliary layer.

The invention discloses a boron diffusion method of a solar cell and the solar cell. The boron diffusion method comprises the following steps: forming a boron-doped layer for a cell substrate in an oxidation furnace tube to obtain a primarily-doped boron substrate, the boron-doped layer comprising a deep-junction boron diffusion layer and a borosilicate glass layer which are laminated from inside to outside; taking out the primarily-doped boron matrix from the oxidation furnace tube, and cooling the primarily-doped boron matrix until the cooled temperature is not higher than 200 DEG C; putting the cooled primarily-doped boron substrate into the preheated oxidation furnace tube again, and heating the primarily-doped boron substrate in an oxygen-free environment to activate non-active boron atoms in the boron-doped layer; and carrying out oxidation source absorption treatment on the deep-junction boron diffusion layer in the primarily-doped boron substrate, and redistributing boron atoms in the deep-junction boron diffusion layer. According to the boron diffusion method, the amount of active boron atoms contained in the surface of the deep-junction boron diffusion layer of the solar cell is increased, the boron doping concentration peak value in the deep-junction boron diffusion layer is reduced, the boron doping concentration distribution is relatively uniform, and the contact resistance between the metal electrode and the deep-junction boron diffusion layer is reduced.

The invention relates to the technical field of photovoltaic cells, and discloses a PN junction of a photovoltaic cell, a preparation method of the PN junction and a preparation method of the photovoltaic cell. According to the preparation method of the PN junction, a thickened first intrinsic amorphous silicon layer is formed on the back surface of a silicon wafer, and then the first intrinsic amorphous silicon layer in a P region is thinned to a normal thickness through patterning, so that a thickness difference is formed between the first intrinsic amorphous silicon layers in an N region and the P region; the thickness difference is used for controlling the boron doping concentration of the boron-doped polycrystalline silicon layers of the N region and the P region (the larger the thickness of the intrinsic amorphous silicon layer is, the smaller the boron doping concentration is); thus, the doping concentration of the N-region boron-doped polycrystalline silicon layer can be reduced to reduce the etching difficulty, the high doping concentration of the P-region boron-doped polycrystalline silicon layer can be maintained, double masks are not needed, the productivity is improved, the problems of recombination, poor electrode preparation and the like caused by the height difference of the N-region and P-region doped polycrystalline silicon layers are solved, the manufacturing cost is low, and the yield is high. And compounding caused by mutual doping is avoided, and the electrical performance of the battery is improved.

The invention belongs to the technical field of machining and cutting, and particularly relates to a temperature-sensing diamond cutter with local boron-doped cutting edges and a manufacturing method of the temperature-sensing diamond cutter. The temperature-sensing diamond cutter with the local boron-doped cutting edge comprises a diamond single crystal substrate, the diamond single crystal substrate has a certain thickness, a local boron-doped diamond single crystal layer is deposited at a corner position of the top surface of the diamond single crystal substrate, the corner position is used for arranging the cutter cutting edge, and the local boron-doped diamond single crystal layer is deposited at the corner position of the top surface of the diamond single crystal substrate. The local boron-doped diamond single crystal layer can be used as a temperature sensor to sense the temperature of an ultra-precise cutting edge micro-area by using the negative temperature coefficient thermosensitive characteristic of the local boron-doped diamond single crystal layer as a P-type semiconductor. Insulation of the outer surface of the boron-doped diamond layer is achieved, and the problem that when the tool cuts various workpieces with high conductivity, due to the fact that the thermal sensitive characteristic of the boron-doped diamond layer is affected by electric conduction between the tool and chips, the cutting temperature cannot be measured is solved.

The invention relates to the technical field of photovoltaic cells, and discloses a selective passivation contact structure, a preparation method thereof and application of the selective passivation contact structure to preparation of a selective TOPCon cell. The method comprises the steps that a first tunneling oxide layer, first thin intrinsic amorphous silicon with the high crystallization rate and second thick intrinsic amorphous silicon with the low crystallization rate are sequentially prepared on the back face of a silicon wafer; boron diffusion doping is carried out, so that the first boron-doped polycrystalline silicon and the second boron-doped polycrystalline silicon have difference in doping concentration and crystallization rate; in the alkali etching process after laser patterning, first boron-doped polycrystalline silicon and a first tunneling oxide layer in a back non-electrode contact area are reserved by utilizing the etching rate difference of an alkaline solution on BSG and two layers of boron-doped polycrystalline silicon with different doping concentrations and crystallization rates; and the first tunneling oxide layer, the first boron-doped polycrystalline silicon and the second boron-doped polycrystalline silicon in the back electrode contact region are reserved. According to the method, the process steps can be simplified, parasitic absorption and recombination are reduced, passivation and transverse transmission are improved, and the cell efficiency is improved.

The invention provides a method for improving passivation contact performance of a p region of a TBC battery, which comprises the following steps of: pretreating an n-type monocrystalline silicon wafer, depositing a SiO2 layer and boron (B) doped polycrystalline silicon (poly-Si), etching, performing laser ablation and the like, then depositing phosphorus (P) doped poly-Si, and finally depositing a passivation and anti-reflection layer and preparing a metal electrode. A tunneling oxide layer and boron in-situ doped polycrystalline silicon are deposited in a p region by adopting an ultra-low temperature plasma enhanced chemical deposition (PECVD) mode, the reaction of SiH4 and N2O is introduced to improve the deposition effect of the oxide layer at low temperature, the compactness of a film layer at low temperature is ensured to improve the separation of B on a SiO2 / c-Si interface, and the passivation performance is improved; b doping poly-Si is adopted in the p region, meanwhile, processing is matched with a nanosecond laser, non-equilibrium doping of the B to the poly-Si is achieved, the ultrahigh doping concentration is obtained, the p region passivation performance of the TBC is improved, and then the open-circuit voltage and the conversion efficiency of the TBC battery are finally improved.

The invention discloses a modification mode and application of a cobalt-free lithium-rich manganese-based positive electrode material, and belongs to the technical field of lithium ion battery positive electrode materials. The preparation method specifically comprises the following steps: preparing a cobalt-free lithium-rich manganese-based precursor by adopting a coprecipitation method, uniformly mixing the cobalt-free lithium-rich manganese-based precursor with a lithium source and a boron source according to a certain proportion, and performing primary burning treatment in air; uniformly mixing the boron-doped cobalt-free lithium-rich manganese-based positive electrode material with an ammonia source according to a certain mass percent, and carrying out secondary burning treatment in a protective atmosphere; and naturally cooling to obtain the surface-modified cobalt-free lithium-rich manganese-based positive electrode material. The cobalt-free lithium-rich manganese-based positive electrode material obtained by the method sequentially comprises a bulk-phase boron-doped layered structure and a spinel structure with oxygen vacancies on the surface from inside to outside; the modified positive electrode material has the characteristics of high specific discharge capacity, high first efficiency, good cycle performance, good rate capability, small voltage drop and less gas production, and has the advantages of low cost, easiness in preparation and large scale.

The invention belongs to the technical field of lithium ion battery negative electrode materials and coated asphalt, and discloses a preparation method and application of a coating material easy to graphitize. The preparation method comprises the following steps: by taking one or more than two of petroleum residual oil, ethylene tar, medium and low temperature coal tar, coal pitch, petroleum pitch and maltha as raw materials, adding a blending solvent and a catalyst to obtain a blending raw material; the easily-graphitized coating material with relatively low interlayer spacing after carbonization is obtained by sequentially carrying out blending solvent compounding, boron doping and pressurized polymerization or sequentially carrying out blending solvent compounding, boron doping, pressurized polymerization, oxidation crosslinking and reduced pressure distillation / molecular distillation processes. The graphitization performance of the asphalt material is remarkably improved through boron doping, so that the asphalt material can form an ordered carbon layer structure at 1200 DEG C, carbonization shrinkage and microcrack generation are inhibited, and the compactness and uniformity of a coating layer are improved. The obtained coating material is suitable for the negative electrode of the lithium ion battery, and the first charge reversible capacity, the cycle stability and the rate capability of the battery can be improved.

A boron-doped graphene composite solid-state electrolyte and its preparation and application. A mixed solution of polyacrylonitrile (PAN) and N,N-dimethylformamide is prepared into a PAN porous film using electrospinning technology. A PEO casting solution is prepared by mixing boron-doped graphene, polyethylene oxide, lithium bis(trifluoromethanesulfonylimide), and acetonitrile. This solution is then cast onto the PAN porous film and, after vacuum drying, forms a composite solid-state electrolyte with polyacrylonitrile fibers as a support, polyethylene oxide as a matrix, and boron-doped graphene as a filler. The composite solid-state electrolyte prepared by the present invention has high ionic conductivity and lithium ion transference number, providing lithium batteries with good rate performance and cycle stability.

The invention provides a boron gradient-doped positive electrode precursor and a preparation method thereof, a positive electrode material and a battery. The positive electrode precursor comprises a boron-doped ternary material core and a boron-doped ternary material layer coated outside the boron-doped ternary material core, the mass fraction of the boron element in the boron-doped ternary material core is lower than that of the boron element in the boron-doped ternary material layer. In the boron gradient-doped positive electrode precursor provided by the invention, boron doping is performed in the boron-doped ternary material core and the boron-doped ternary material layer, so that a B-O bond with relatively high bond energy is formed, and lattice stress accumulation in the positive electrode precursor is reduced, thereby improving the structural stability and thermal stability of the positive electrode precursor and the positive electrode material; in addition, through gradient doping of boron, the electrochemical performance of the positive electrode material is ensured, the surface and interface structure of the positive electrode precursor is strengthened, the expansion of cracks is inhibited, and the structural stability of the positive electrode precursor is improved.

The invention discloses a nitrogen / boron-doped non-noble metal-based material, a synthesis method thereof and application of the nitrogen / boron-doped non-noble metal-based material in a microbial fuel cell. According to the method, a carbon fiber brush is used as a substrate, urea and sodium borohydride are used as a nitrogen source and a carbon source respectively, and the nitrogen / boron doped non-noble metal-based material is synthesized through a hydrothermal method. The electrostatic interaction between graphene oxide and FeCoNi-LDH is utilized to realize tight combination, so that FeCoNi-LDH nanosheets are uniformly dispersed on the surface of the carbon fiber brush, and the problems that LDHs are easy to agglomerate and poor in conductivity are solved; in the boron / nitrogen co-doping process, an efficient electron transmission channel is constructed by adjusting the electronic structure of the composite material, and the material is endowed with excellent electron transmission capability and oxygen reduction performance. In an MFC (Microbial Fuel Cell) test constructed by taking a nitrogen / boron-doped non-noble metal-based material as a cathode, the output voltage and the maximum power density are several times of those of commercial Pt / C and a blank carbon fiber brush, and the carbon fiber brush has a wide application prospect in the field of microbial fuel cells.

The invention discloses an atomic layer deposition method and structure for an aluminum fluoride enhanced aluminum oxide passivation layer of a TOPCon solar cell. The method comprises the steps that after a boron-doped layer is formed on the front face of a crystal silicon wafer, a passivation layer is formed on the boron-doped layer through an atomic layer deposition technology, specifically, Al2O3 deposition circulation is conducted with trimethyl aluminum as an aluminum source and H2O as an oxygen source, AlF3 deposition circulation with aluminum chloride as the aluminum source and HF or NH4F as a fluorine source is periodically inserted, the proportion of the number of deposition circulation times of AlF3 to the number of deposition circulation times of Al2O3 is 1: (1-10), and the passivation layer is formed on the boron-doped layer through the atomic layer deposition technology. And an alternating layer structure with the total thickness of 5-10 nm is formed. According to the invention, an AlF3 layer is periodically inserted in an Al2O3 deposition cycle, so that an Al2O3 / AlF3 superlattice structure is formed. According to the structure, the interface passivation effect is remarkably improved, hydrogen atom overflow is reduced, and the ultraviolet aging resistance is enhanced. The method is compatible with an existing ALD production line, is suitable for high-efficiency TOPCon battery manufacturing, and has a good industrial application prospect.

The embodiment of the invention relates to the field of photovoltaic technology, and provides a solar cell and a preparation method thereof, and a solar cell production line. The preparation method of the solar cell comprises the following steps: forming a first lamination layer comprising a first tunneling layer, a boron-doped polycrystalline silicon layer and a first mask layer on a first surface of an N-type silicon substrate; corresponding parts of the first lamination layer and the N-type silicon substrate in the second region and at least part of the spacer region are removed, so that a groove is formed in the N-type silicon substrate, and the groove surface, formed in the N-type silicon substrate, of the groove is arc-shaped; forming a second lamination layer comprising a second tunneling layer, a phosphorus-doped polycrystalline silicon layer and a second mask layer which are laminated in sequence on the whole side of the first surface; the winding plating layer is removed, the winding plating layer is wound and plated on the second surface of the N-type silicon substrate when the first lamination layer and / or the second lamination layer are / is formed, and the second surface is opposite to the first surface; removing corresponding parts of the second lamination layer in the first region and the spacer region; and removing the first mask layer and the second mask layer.

The invention provides a lithium manganese iron phosphate composite positive electrode material and a preparation method thereof, and relates to the technical field of lithium batteries. The lithium manganese iron phosphate composite positive electrode material is of a core-shell composite structure; wherein the core is lithium manganese iron phosphate; the first coating layer and the second coating layer are sequentially arranged on the outer surface of the core; the first coating layer is made of Cu-Ti alloy; the second coating layer is a boron-doped carbon material; a B-Ti chemical bond is arranged between the Ti element in the first coating layer and the B element in the second coating layer. According to the unique double-layer core-shell structure of the material, through the conductive and firm Cu-Ti alloy and the boron-doped carbon coating layer, the rate capability is improved, and meanwhile, the volume change of the core material is effectively inhibited, so that the cycling stability and safety are enhanced. The key B-Ti chemical bond ensures the tight combination and integrity of the coating layer, and is the basis for realizing long-acting stable protection.

The invention provides an amorphous carbon coated lithium manganese iron phosphate positive electrode material and a preparation method and application thereof, the preparation method comprises the following steps: mixing a lithium source, a ferrous source, a manganese source, a phosphorus source, a carbon source and a solvent to obtain mixed slurry; carrying out spray drying treatment on the mixed slurry, and carrying out plasma treatment on the obtained dried material to obtain a precursor material; and mixing the precursor material with a boron source, and sintering to obtain the amorphous carbon coated lithium iron manganese phosphate positive electrode material. The surface of the lithium manganese iron phosphate positive electrode material is coated with the amorphous carbon layer, the bonding strength of the amorphous carbon coating layer and the positive electrode material is high, the problem of electronic conductivity of the lithium manganese iron phosphate positive electrode material is solved, and meanwhile, the ionic conductivity of the material is improved through boron doping.

The application relates to the technical field of lithium ion battery materials, and discloses a low-expansion silicon-carbon material and a preparation method thereof. The low-expansion silicon-carbon material has a porous core-shell structure, the inner core is graphene / metal-doped amorphous carbon-coated nano silicon, and the shell is boron-doped amorphous carbon. The preparation method comprises the following steps: firstly, a silicon oxide compound, a graphene oxide solution and an organic metal polymer are added into an organic carbon source solution, spray drying is carried out, and an oxidized graphene-coated metal-doped silicon oxide precursor material is obtained through reaction; secondly, a mixed gas of a boron source gas and argon is introduced into the oxidized graphene-coated metal-doped silicon oxide precursor material, and a boron-doped silicon-carbon composite material is obtained through reaction; and thirdly, the boron-doped silicon-carbon composite material is soaked in a hydrofluoric acid solution, and the low-expansion silicon-carbon material is obtained after drying. Through the technical scheme, the problems of high expansion and poor rate performance of the silicon-carbon material in the related art are solved.

The invention relates to the technical field of electrode materials, in particular to a nitrogen-boron-silicon-carbon negative electrode material and a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: mixing an organic carbon source, an organic nitrogen source, a boron source, a cross-linking auxiliary agent and a solvent, and sequentially carrying out cross-linking reaction and calcination to obtain a nitrogen-boron-doped porous carbon matrix; carrying out silicon or silicon-boron deposition on the nitrogen-boron-doped porous carbon matrix and reaction gas in a fluidized state to obtain a silicon-carbon precursor; the reaction gas is mixed gas of silane and borane or silane; and coating the silicon-carbon precursor with a mixed gas of a carbon source, a nitrogen source and a boron source in a fluidized state to obtain the nitrogen-boron-silicon-carbon negative electrode material. The nitrogen-boron-silicon-carbon negative electrode material prepared by the preparation method disclosed by the invention has excellent cycle performance, rate charge-discharge performance and relatively low expansion effect.