45results about How to "Reduce rebound rate" patented technology

The invention discloses a low-carbon high-compactness shotcrete elasticity reducing agent and a preparation method and application thereof, and relates to the field of building material concrete admixtures, the elasticity reducing agent comprises the following components by mass: 53-73% of a rheological component, 15-25% of a tackifying component, 10-18% of an early strength component, and 0.5-4% of a setting adjusting component; the rheological component comprises manganese slag powder and silica fume, and the tackifying component is tailing powder loaded with nano modified cellulose ether. The viscosity of sprayed concrete is increased through the tackifying component, the slurry wrapping property of the concrete is improved, the yield stress of the concrete is improved through the rheological component, and the early strength component is combined to synergistically improve the wall-adhering and quick-hardening properties after the material is sprayed, so that the rebound rate is reduced; the nano-particles loaded on the organic matter are hydrated in pores, harmful pores are directionally filled, the compactness and strength of the sprayed concrete are effectively improved, and low-carbon, low-resilience and high-compactness of the sprayed concrete are achieved.

The invention provides an early-strength quick-hardening alkali-free powdery quick-setting material and a preparation method thereof. The raw materials specifically comprise a flash coagulation component, a coagulation adjusting component, a drying and stabilizing component, a reinforcing component, a grinding aiding component and a thickening component. The percentage of each component is as follows: 45wt%-55wt% of the flash setting component, 3wt%-10wt% of the setting adjusting component, 5wt%-15wt% of the drying stabilizing component, 25wt%-35wt% of the reinforcing component, 1wt%-5wt% of the grinding aid component and 2wt%-8wt% of the thickening component. The early-strength quick-hardening alkali-free powdery quick-setting material disclosed by the invention can simultaneously meet the following requirements: (1) the initial setting time of neat paste is less than 2min, and the final setting time is less than 3min; (2) the 1d strength of the mortar is greater than 13MPa, the 28d compressive strength ratio is greater than 105%, and the 90d strength retention rate is greater than 110%; (3) the alkali content (in terms of Na2O equivalent) is lower than 0.5%; (4) the compatibility with cement of different manufacturers is good, the use dosage is low, and good popularization and application values are achieved.

The invention relates to a micro-nano aggregate based on silanized calcium sulfate whisker in-situ polymerization, the main component of the micro-nano aggregate is acrylate copolymerized CSW / NS-GO, and the preparation method comprises the following steps: loading nano silicon dioxide on the surface of calcium sulfate whisker to obtain CSW / NS; carrying out silanization modification on CSW / NS; preparing graphene oxide by a Hummers method; and carrying out in-situ polymerization to prepare the acrylate copolymerized CSW / NS-GO. Calcium sulfate whiskers are loaded and bonded with epoxy modified nano silicon dioxide and then subjected to in-situ polymerization with graphene oxide in an acrylic monomer, a polymer chain is tightly combined with a functional group of CSW / NS-GO, good interface bonding is formed, and the strength and toughness of the composite material are improved. The acrylate copolymerized CSW / NS-GO has a microscopic three-dimensional network structure and excellent stability, so that the internal structure of the concrete is more compact, the porosity is reduced, the permeation of water is prevented, and the invasion of harmful substances such as chloride ions and sulfate ions into channels is reduced, thereby reducing the structural damage caused by environmental factors such as dry-wet cycle and freeze-thaw cycle; the durability of the concrete is improved.

The invention relates to the technical field of concrete preparation, in particular to sprayed concrete with high crack resistance and low rebound rate and a preparation method thereof. The nano aerogel, the polypropylene fiber and the modified vermiculite are creatively adopted to prepare the sprayed concrete, and the nano aerogel has the water retention and moisture absorption characteristics and plays an internal curing role in the concrete, so that the internal water loss rate is reduced, the shrinkage of the concrete is weakened, and the concrete is prevented from being damaged. Meanwhile, the polypropylene crude fiber with high breaking strength and elasticity modulus and a composite cross-linked network structure formed by the polypropylene crude fiber and the modified vermiculite can greatly improve the crack resistance and durability of the sprayed concrete under the interaction; furthermore, when the concrete is cracked, the modified liquid flows out of the inner cavity of the vermiculite and is adhered and cured at the crack to realize a self-repairing effect, so that the structural deformation of the tunnel can be better limited, and the service life of the tunnel lining in a complex environment is prolonged.

The invention provides a springback-reducing admixture for sprayed concrete and a preparation method of the springback-reducing admixture, and relates to the technical field of concrete admixtures. The springback-reducing admixture for the sprayed concrete comprises the following raw materials in percentage by mass: 40-70% of a component A and 30-60% of a component B, the component A comprises the following raw materials in percentage by mass: 30%-50% of calcined kaolin, 10%-20% of light calcined magnesia and 40%-60% of semi-hydrated gypsum. And the component B comprises the following raw materials in percentage by mass: 60-90% of cement, 5-10% of modified rubber powder and 5-10% of cellulose. The springback-reducing admixture for sprayed concrete provided by the invention is applied to sprayed concrete and has relatively low springback rate and relatively high strength.

The invention belongs to the technical field of civil engineering materials, and particularly relates to a lightweight jet engineering cement-based composite material as well as a preparation method and application thereof. The lightweight jet engineering cement-based composite material comprises the following components: cement, fly ash, silica fume, hollow fly ash microspheres, water, organic fibers, a water reducing agent and a thickening agent. According to the invention, by optimizing the raw material ratio, not only is the density of the jet ECC significantly reduced and the lightweight of the material realized, but also the fluidity, the adhesion property and the mechanical property of the material are greatly improved, and the problems of poor adhesion, high rebound rate and limited jet thickness of the traditional jet ECC are solved; in the spraying process, the cement-based composite material shows low rebound rate and large spraying thickness, and a light spraying engineering cement-based composite material with excellent performance is provided for engineering application.

The invention provides a low-cost admixture for shotcrete and a preparation method thereof. The raw materials for preparing the admixture include the following components by weight percentage: 40% to 50% silica fume, 5% to 10% fast-hardening sulphoaluminate cement, 35% to 45% reinforcing agent, 2% to 4% dispersant, 1% to 2% shrinkage reducing agent, and 0.5% to 1% regulator. The raw materials for the shotcrete admixture are widely available, cheap and easy to obtain, can significantly improve the cohesiveness and pumpability of the shotcrete, shorten the setting time of the shotcrete, have high bonding strength with the rock base, reduce the rebound rate of the shotcrete, and greatly save the project construction cost.

The invention discloses a car rear floor drawing die structure, and relates to the technical field of drawing dies, the car rear floor drawing die structure comprises an upper die mechanism, an edge pressing mechanism and a lower die mechanism, the upper die mechanism is located above the lower die mechanism, the edge pressing mechanism is located at the top of the lower die mechanism, and the upper die mechanism comprises an upper die base; a plurality of buffer grooves are formed in the bottom of the upper die base, the blank pressing mechanism comprises a blank pressing ring, the blank pressing ring is used for pressing a plate and preventing wrinkling and cracking, a plurality of buffer male dies are arranged at the top of the blank pressing ring and used for being matched with the buffer grooves to form a buffer area on the plate, and the lower die mechanism comprises a lower die base. The production efficiency of the car rear floor is improved, meanwhile, a plate can be limited, the situation that the forming quality is affected due to the fact that the position of the plate deviates before the plate is pressed is avoided, the rebound probability of the formed plate can be reduced, and the quality of the formed car rear floor is improved.

The invention discloses a damaged carton recycling device and method for carton packaging, and relates to the technical field of waste recycling, the damaged carton recycling device comprises a shell, two door bodies rotationally installed on the shell, a control module fixedly installed outside the shell and a data display module, the compaction assembly is mounted in the shell; the hydraulic rod is fixedly mounted at the top of the shell; and the compaction assembly comprises a bottom plate fixedly mounted at the bottom of the shell and an extrusion plate slidably mounted in the shell, a connecting sleeve is fixedly mounted on the extrusion plate, and the driving end of the hydraulic rod is fixedly connected with the connecting sleeve. The carton compacting device has the advantages that in the carton compacting process, through pressure equalizing and buffering of the pressure buffering assembly, negative pressure air exhaust gap discharging and resistance reducing, lateral protection restraining deformation and repeated tamping successive exhaust plastic deformation, the interlayer fitting degree and uniformity of paperboards can be synergistically improved, and the higher compression ratio and the lower rebound rate are achieved.

The present invention discloses a shotcrete modifier and a preparation method and application thereof. The shotcrete modifier comprises the following components by mass percentage: 50-70 parts of metakaolin, 20-30 parts of an exciting component, 10-20 parts of a shrinkage reducing component, 1.5-2 parts of a water reducing agent, 0.2-0.5 parts of a consistency modifier, and 1-2 parts of a setting regulating component. The specific surface area of ​​the metakaolin is 10000-15000 m 2 / kg, the total content of Al2O3 and SiO2>85%; the activating component is anhydrous gypsum, which is composed of one or more of natural anhydrite and calcined gypsum; the shrinkage reducing component is composed of organic shrinkage reducing compounds and inorganic nano mineral powder. When used, the modifier replaces the cement in the shotcrete at a dosage of 15%~20%. The modifier significantly improves the volume stability of shotcrete and reduces the risk of concrete cracking. At the same time, the rebound rate of shotcrete is significantly reduced, the early strength and density are significantly improved, and the later strength is also increased. The crack resistance and anti-seepage performance of shotcrete are significantly improved, and the anti-sulfate durability is also improved.

The invention belongs to the technical field of concrete, and particularly relates to basalt fiber composite modified sprayed concrete and a preparation method thereof. The basalt fiber composite modified sprayed concrete is prepared from the following raw materials in parts by weight: 420 to 470 parts of cement, 200 to 220 parts of water, 830 to 860 parts of sand, 840 to 880 parts of gravel, 40 to 60 parts of admixture, 15 to 30 parts of modified basalt fiber, 2 to 6 parts of polycarboxylate superplasticizer and 5 to 12 parts of alkali-free accelerator. The modified basalt fiber is added into the sprayed concrete to serve as a reinforcing phase, the strength and impact toughness of the concrete can be improved, and the later strength of the concrete is guaranteed. The cerium trifluoride modified fly ash is added into the admixture, so that the rebound rate can be reduced, and the early strength of the concrete is improved.

The utility model discloses battery cell processing equipment and a production line. The battery cell processing equipment is used for processing cylindrical battery cells. The cylindrical battery cell comprises a shell and an end cover, an opening is formed in the shell in the axis direction of the shell, and the battery cell processing equipment is used for enabling the end cover to cover the opening. The battery cell processing equipment comprises a fixing part, a first bending assembly and a second bending assembly. The fixing part is used for fixing the shell. The first bending assembly is suitable for being connected with the end cover and used for driving the end cover to be bent by a first angle around a first axis relative to the shell, and the first axis is perpendicular to the axis of the shell. The second bending assembly is suitable for being connected with the end cover and used for driving the end cover to be bent by a second angle around a second axis relative to the shell, and the second axis is parallel to the first axis. The first bending assembly and the second bending assembly jointly drive the end cover to be bent relative to the shell, so that the end cover covers the opening. According to the battery cell processing equipment and the production line, the cover closing precision of the battery cell can be improved, and the yield of the cylindrical battery cell is guaranteed.

The invention relates to the technical field of concrete preparation, in particular to high-strength and low-resilience sprayed concrete and a preparation method thereof. The sprayed concrete is prepared from the composite modified fibers and the modified montmorillonite, so that the prepared concrete has high crack resistance and high durability, and the characteristics of small particle size and large specific surface area of the liquid SiO2 are utilized, so that the rebound rate of the sprayed concrete is directly reduced, and the durability of the sprayed concrete is improved. When the modified montmorillonite is uniformly dispersed into a cross-linked network system of the composite modified fibers and the modified montmorillonite, the chemical bonding capability of the modified montmorillonite and the composite modified fibers can be enhanced, the rebound rate of the sprayed concrete is further reduced, and the crack resistance and durability of the sprayed concrete are improved, so that the structural deformation of a tunnel can be better limited, and the service life of the tunnel is prolonged. And the service life of the tunnel lining in a complex environment is prolonged.

The application discloses a shotcrete rebound-reducing agent and a preparation method thereof. The shotcrete rebound-reducing agent is prepared from the following raw materials in mass percentage: 15-30% of a quick-setting component, 2-5% of a viscosity-increasing component, 10-15% of a reinforcing component, 2-5% of an anti-freezing component, 1-4% of a stabilizer, and the rest of water; and the viscosity-increasing component is a combination of polyvinylpyrrolidone and modified carboxymethyl cellulose. The prepared shotcrete rebound-reducing agent has the advantages of good sprayability, high hourly strength, good anti-freezing and stability, and the like, can improve the working performance of shotcrete, reduce the content of a quick-setting agent and significantly reduce the rebound rate of shotcrete, and has good economic benefits.

The utility model discloses an integrated straightening comb, including control portion, with control portion electricity connection's straightening portion, the power connection portion of providing power supply to control portion and assembly control portion, straightening portion and shell, straightening portion is provided with first comb row, second comb row, heating portion and refrigeration fan, and second comb row assembly is in first comb row, and first comb row is provided with a plurality of first comb teeth, and second comb row is provided with a plurality of second comb teeth and second comb row, and second comb tooth is perpendicular to connect with second comb tooth, heating portion is controlled by control portion, is used to first comb row heating, and refrigeration fan is controlled by control portion, is used to second comb row cooling, compared with depending on natural cooling or external blow, the coupling structure of the application significantly shortens straightening setting time and improves consistency.

This invention discloses a low-carbon, high-density shotcrete admixture, its preparation method, and its application, relating to the field of concrete admixtures in building materials. The admixture comprises the following components by mass percentage: 53-73% rheological component, 15-25% thickening component, 10-18% early-strength component, and 0.5-4% setting regulator component. The rheological component includes manganese slag powder and silica fume, and the thickening component is tailings powder loaded with nano-modified cellulose ether. This invention increases the cohesiveness of shotcrete and improves the slurry encapsulation of concrete through the thickening component, increases the yield stress of concrete through the rheological component, and synergistically improves the adhesion and rapid hardening performance of the material after spraying by combining with the early-strength component, thereby reducing the rebound rate. Furthermore, the nanoparticles loaded on organic matter hydrate in the pores, directionally filling harmful pores, effectively improving the density and strength of shotcrete, achieving low-carbon, low-rebound, and high-density shotcrete.

The application belongs to the technical field of battery pole piece production, and particularly relates to a battery pole piece automatic rolling equipment and a use method thereof. In view of the problem that the distance between upper and lower rollers of an existing rolling pair roller machine is not easy to adjust, thereby limiting the use range of the lithium battery pole piece rolling pair roller machine, the following scheme is provided. The scheme comprises a U-shaped base, a first adjusting extrusion roller and a first fixed extrusion roller, the first adjusting extrusion roller and the first fixed extrusion roller are arranged in the U-shaped base to roll the battery pole piece, a second adjusting extrusion roller and a second fixed extrusion roller, the second adjusting extrusion roller and the second fixed extrusion roller are arranged on the other side in the U-shaped base to roll the battery pole piece for the second time to prevent rebound, and two groups of lifting mechanisms, which ensure the thickness consistency of the battery pole piece and prevent rebound.

The present invention relates to a lithium battery, a negative electrode sheet of a lithium battery and a preparation method thereof. The preparation method of the negative electrode sheet of a lithium battery comprises: coating a negative electrode slurry on a current collector, drying and rolling three times in sequence to obtain a negative electrode sheet, wherein the thickness after the first rolling is H1, the thickness after the second rolling is H2, the target thickness of the negative electrode sheet is H3, H3 / H1=A1, H3 / H2=A2, A1 is 60%~90%, and the difference between A2 and A1 is 5%~30%. The preparation method of the negative electrode sheet provided by the present invention, through three rolling processes with a specific roller ratio, is not only conducive to improving the uniformity of the rolling process of the negative electrode sheet, avoiding the rupture and pulverization of the active material in the negative electrode sheet, and effectively improving the stability of the solid electrolyte interface film, but also can effectively reduce the rebound rate of the negative electrode sheet, ensure the compaction density and thickness of the negative electrode sheet, thereby improving the high temperature storage performance of the lithium battery.

The invention provides a secondary battery and a preparation method thereof, a negative pole piece and an electric device, the secondary battery comprises the negative pole piece, the negative pole piece comprises a negative current collector and a negative film layer arranged on at least one side of the negative current collector, the negative film layer comprises a negative active material, and the negative active material comprises a carbon material; at least part of the surface of the carbon material is coated with fibers, and the rebound rate of the negative pole piece is 20-40%.

A shaping die and shaping method for shape memory patching tubes, belonging to the technical field of industrial transmission pipeline repair. The present invention solves the problem that the existing shaping die is prone to cause the patching tube to rebound when pressurizing and shaping the multi-petal patching tube. It also includes at least two fixing rods, the upper end surface of the base is processed with a first arc-shaped ridge along its length direction, the pressure rod is horizontally fixed to the pressure head of the press and is located directly above the patching tube, the number of the fixing rods is an even number and they are arranged opposite to each other on the outside of the patching tube, the side of the fixing rod close to the patching tube is processed with a second arc-shaped ridge, and the two oppositely arranged fixing rods have their ends fixed by bolts, and the pressure rod, the first arc-shaped ridge and the second arc-shaped ridge are pressed one by one into the groove between each adjacent two petals on the shaping column.

The invention relates to a tunnel primary support sprayed concrete calcium ion curing anti-crystallization construction method, which comprises the following steps of: (1) looking up construction drawing geological exploration data, and pre-judging the water content condition of a tunnel site; (2) sampling surrounding rock fissure water: after the tunnel is excavated, arranging 1-2 sampling points at a water outlet part which has strand-shaped or continuous drop-shaped water outlet and is not polluted by primary support sprayed concrete on a fresh rock surface, and sampling the surrounding rock fissure water; (3) sending the surrounding rock fissure water to a professional detection mechanism for detection and issuing a detection report, and combining the detection report with a water quality test report in a design file for analysis to obtain ion concentration values of HCO3 <-> and SO4 < 2-> in the tunnel site area; (4) when the total ion concentration value is less than or equal to 150mg / L, performing according to a conventional preliminary bracing construction process; and when the total ion concentration value is greater than 150mg / L, implementing an anti-crystallization control measure. The method has the advantages of low construction cost, simplicity in construction and good anti-crystallization effect.

The invention relates to a progressive striking type high-frequency compaction assembly line. The progressive striking type high-frequency compaction assembly line comprises operation equipment and a bearing component. The operation equipment comprises a preheating part, a high-frequency hot-pressing part and a water-cooling cold-pressing wood striking part; the high-frequency hot-pressing part comprises a plurality of high-frequency hot-pressing machines, a moving roller way of each high-frequency hot-pressing machine extends from an internal hot-pressing station to inlets and outlets in the two sides to be exposed, and the adjacent exposed moving roller ways are in butt joint; the water-cooling cold-pressing wood striking part comprises a plurality of water-cooling cold-pressing machines, a movable roller way of each water-cooling cold-pressing machine extends and is exposed towards inlets and outlets in the two sides from an internal pressing station, and the adjacent exposed movable roller ways are in butt joint; the bearing component is a tray which is arranged below the wood board and used for bearing the wood board. According to the production line, the high-frequency hot-pressing part, the water-cooling cold-pressing wood striking part and the bearing component are used, on the premise that the thickness of a wood board is allowed to rebound, the technical problems that in the prior art, due to the fact that an upper pressing plate and a lower pressing plate are needed for clamping and pressure maintaining, operation is complex, and process step adjustment is limited in the production line circulation process are solved, and the rebound problem is solved.

The application relates to a composite high-strength supporting material and a preparation method and construction process thereof. Tailings sand powder in the application plays a certain lubricating role in the system and can reduce the slurry viscosity; the prepared special polycarboxylic acid water reducing agent has a micro-crosslinking structure and multiple adsorption groups, has extremely strong adsorption capacity on cement and tailings sand, and can reduce the slurry viscosity; the prepared organic polymer can quickly form an interpenetrating network structure with the cement-based material on the sprayed base surface, improves the slurry adhesion speed, reduces the spraying rebound rate, and effectively improves the strength, heat resistance, flame resistance and surface protection capacity of the target supporting material by introducing rigid / heat-resistant structures, flame-resistant structures and hydrophobic structures; the prepared high-strength supporting material has super-high compressive strength and bonding strength, fast hardening speed after spraying, excellent anti-cracking performance and good durability, improves the utilization rate of solid waste resources, has a simple and convenient construction process and high efficiency, and is suitable for construction in various complex environments.

This invention provides a rebound reducer for shotcrete used in tunnel engineering and its preparation method. The raw materials of the rebound reducer for shotcrete used in tunnel engineering of this invention have the following mass fractions: 10-15% thickening component, 10-15% nano-active mineral component, 5-10% reinforcing component, 1-2% suspension stabilizing component, 2-3% water-retaining component, 2-3% workability adjusting component, and the remainder being water. The rebound reducer for shotcrete used in tunnel engineering is used at 3-5% of the cementitious material. This rebound reducer can effectively reduce the rebound rate of shotcrete, making it less than 15%, and can significantly improve the compactness of concrete, while enhancing its cohesiveness and fluidity, meeting the construction requirements of shotcrete in tunnel engineering, and maintaining the workability and durability of concrete.

The present application relates to the field of concrete admixtures, and specifically discloses a highly efficient enhanced shotcrete admixture and its application. A highly efficient enhanced shotcrete admixture comprises the following raw materials by weight: 10-30 parts of polycarboxylic acid water reducer; 15-30 parts of plant glue; 80-110 parts of nanofiber and epoxy resin composite; 30-70 parts of accelerator; 5-10 parts of water; the nanofiber and epoxy resin composite is a composite of long-chain silane-modified nanofiber and fluorine-containing epoxy resin emulsion. By adjusting the type and dosage of each raw material, the present application obtains a high-efficiency enhanced shotcrete with a minimum rebound rate of 6.25%, which effectively reduces the rebound rate of the high-efficiency enhanced shotcrete.

The invention relates to sprayed concrete and a preparation method thereof, and relates to the technical field of concrete.The sprayed concrete is prepared from, by weight, 365-410 parts of cement, 790-830 parts of fine aggregate, 710-760 parts of coarse aggregate, 70-100 parts of fly ash, 75-95 parts of modified yellow phosphorus slag, 12-16 parts of accelerator, 4.5-7 parts of water reducer, 3-6.5 parts of natural plant admixture and 155-175 parts of water; the natural plant additive is prepared from beet root tubers and gelidium amansii in a weight ratio of (1-2): (5-9). On the basis of an existing shotcrete batching system, the natural plant admixture and the modified yellow phosphorus slag are introduced, all the components have a synergistic effect, the construction requirements for the initial strength and the later strength of the shotcrete are met, the rebound rate of the shotcrete is remarkably reduced, and the shotcrete has a good application prospect. The method can be widely applied to construction of various supporting projects such as tunnels and roadways.

The present invention discloses an alkali-free liquid flocculant for nano-sol combined spray coating, a preparation method and application thereof, wherein the alkali-free liquid flocculant is prepared from raw materials including the following mass fractions: 5 to 20 parts of magnesium chloride, 5 to 40 parts of magnesium sulfate, 1 to 3 parts of lithium chloride, 0.01 to 0.5 parts of thickener, 0.1 to 3 parts of water reducer, and 40 to 80 parts of water. The alkali-free liquid flocculant for nano-sol combined spray coating provided by the present invention has the advantages of small addition amount, short flocculation time, fast hardening, etc., and has a significant effect on improving the spraying efficiency of sol combined wet spray coating, reducing the rebound rate, etc.

The application relates to the field of degradable composite material processing technology, and discloses a rebound-preventing groove-pressing shaping device for degradable composite materials, which comprises a rebound-preventing mechanism and a base. The rebound-preventing groove-pressing shaping device for degradable composite materials is provided with two-stage elastic buffering formed by a first spring and a second spring in a shell. When the groove-pressing mechanism is pressed down, the first spring provides initial reverse supporting force first, and the second spring gradually increases the supporting force in cooperation with the telescopic rod with the increase of the pressing depth. The variable-rigidity support can accurately match the rebound stress of the degradable composite material at different deformation stages, reduces the rebound rate, and the damping columns on the two sides of the baffle cooperate with the sliding of the sliding blocks in the sliding grooves to absorb the vibration energy in the pressing process, avoid local stress concentration of the material due to vibration, improve the groove-pressing quality, and the concave groove cooperates with the convex block of the groove-pressing mechanism to form a forming space. The round corners of the bottom sharp tips can reduce the material flow resistance and prevent the material from being scratched during pressing.

The present invention discloses an optimization method for improving the bonding effect of shotcrete, including constructing a correlation function model between the spraying angle of a spraying device and the wall bonding performance, obtaining the initial equipment parameters and the wall bonding force of the spraying device at the construction site; inputting the initial equipment parameters and the wall bonding force into the correlation function model, judging whether the current initial equipment parameters meet the preset conditions; if not, adjusting the initial equipment parameters, repeating the above steps until the preset conditions are met, and obtaining the optimal equipment parameters; setting the spraying device according to the optimal equipment parameters. The bonding performance of the shotcrete on the wall is increased by only reasonably setting the spraying method, especially the spraying angle of the nozzle.

The present application provides a negative electrode active material including a core and a coating layer coating the core, wherein the core is graphite, the coating layer comprises at least one of titanium carbide (TiC), tungsten carbide (WC), chromium carbide (Cr3C2), boron carbide (B4C) and silicon carbide (SiC), and the weight ratio of the coating layer to the graphite is (0.01-0.10):1.