388results about "Lead-acid accumulators construction" patented technology

A positioning and clamping apparatus includes a hoisting unit including a support plate, two piston members, two first actuators, two hoisting plates, and an interconnection plate; a transporting unit including a second actuator, two movement rods, and a transporting plate; and a micro adjustment positioning unit including a limiting plate, two follower plates, two sliding members, a third actuator, and a positioning plate. The positioning and clamping apparatus is used for cell electrode plate groups, lead bridges, and lead heads of a lead-acid battery.

A positioning apparatus includes a support structure including a top plate and legs extending downward from four corners of the top plate; a hoisting unit including a first hoisting plate, piston members, a second hoisting plate, two pressing blocks, and a first actuator; and a clamping unit including two opposite second actuators and two pushing blocks. The positioning apparatus is used for cell electrode plate groups of a lead-acid battery.

The invention discloses a lead-acid battery production process, and relates to the technical field of lead-acid battery production, and the lead-acid battery production process comprises the following steps: S1, lead powder preparation: carrying out grain cutting and closed Balton ball milling on an electrolytic lead ingot to obtain lead powder with BET0.65-0.75 m / g and apparent density 1.10-1.20 g / cm < 3 >, and the nitrogen-sealed oxygen content of a lead powder bin is less than or equal to 5vol%; s2, grid casting: heating the lead-calcium-tin-aluminum alloy to 480 + / -10 DEG C in a lead smelting furnace, and casting the lead-calcium-tin-aluminum alloy into a grid with the thickness tolerance of + / -0.05 mm through a continuous casting machine; s3, performing paste mixing; the device has the advantages that through side insertion of the inverted dovetail groove, isolation of the hydrophilic PET thin sheet and blocking of the top air curtain, condensate is guided to the collecting tank along the thin sheet and is pumped out in real time, no PbSO4 white ring is left on the surface of the polar plate, and the powder falling rate of the follow-up slicing and vibration procedures is remarkably reduced.

The invention provides a continuous negative pressure synchronous rapid electrolyte injection process for a lead-acid storage battery, which comprises the following steps: S1, electrolyte injection pretreatment: firstly, connecting a four-ring coaxial electrolyte injection head with an electrolyte injection port of the lead-acid storage battery, starting a negative pressure vacuum pump to pump the negative pressure of the lead-acid storage battery to initial high negative pressure-85kPa, s2, synchronous electrolyte injection: after the working negative pressure of a negative pressure vacuum pump is adjusted, the electrolyte is immediately injected into the lead-acid storage battery in a continuous negative pressure state, and the pressure, flow and temperature parameters during electrolyte injection are monitored through a monitoring device; and then calculating an optimal pressure relief curve according to the battery model, and standing the lead-acid storage battery after pressure relief is finished, so that the production efficiency of the lead-acid storage battery is improved, gas in a polar plate and a partition plate can be completely discharged, the initial capacity of the battery is improved, and the performance fluctuation of the batteries among batches and in the batches is reduced.

The invention belongs to the technical field of batteries, and particularly relates to a preparation method of a solid lead battery for constructing a sulfuric acid gel solid electrolyte through in-situ polymerization gel forming. Comprising the following steps: mixing a polymeric monomer, a cross-linking agent, a reinforcing component and a sulfuric acid carrier solution, stirring and dispersing to obtain an electrolyte precursor solution; adding the initiation system into an electrolyte precursor solution, uniformly stirring, quickly injecting into a polar plate / partition plate assembly or a to-be-formed battery cell, and standing; performing triggering treatment after infiltration, performing in-situ polymerization and crosslinking to form gel, and curing to obtain a gel solid electrolyte cell; and performing formation, capacity grading and aging treatment on the gel solid electrolyte cell to obtain the solid lead battery. Through a process path of low-viscosity precursor injection-in-situ gel forming in the battery cell-subsequent formation, full infiltration and stable immobilization of electrolyte on a pole plate pore channel and a separator fiber network are realized, so that the risks of liquid leakage and acid mist are reduced, acid layering is inhibited, and the consistency and cycle stability of the battery cell are improved.

This utility model discloses a storage battery applicable to the battery field, comprising an electrode assembly, a busbar, terminals, electrolyte, and a battery casing. Several annular grooves are axially arranged on the outer circumferential surface of the terminals. Anti-corrosion layers are provided on the outer circumferential surface of the terminals, the surface of the busbar facing the terminals, and the outer circumferential surface of the busbar. The portion of the terminals extending into the terminal holes in the battery casing is sequentially filled with a sealing ring, a sealing ring, a pressure nut, and colored adhesive in the direction pointing outwards from the battery casing. The battery casing is provided with a gas vent valve, and a catalyst is placed inside the battery casing near the gas vent valve. This utility model reduces battery water loss by placing a catalyst inside the battery casing near the gas vent valve. By providing anti-corrosion layers on the surfaces of the terminals and busbar, providing annular grooves on the terminal surface, and sealing the terminals to the battery casing, it reduces acid creep and corrosion of the electrolyte.

The invention relates to a battery and an energy storage device. The battery comprises at least two frames which are sequentially stacked and connected along a first direction; the two end plates are connected to the two opposite sides of the at least two frames in the first direction respectively, and a closed space is defined by the two end plates and all the frames; the at least two polar plates and the at least one partition plate are located in the closed space and alternately stacked in the first direction, and the at least two polar plates are fixed to the at least two frames in a one-to-one correspondence mode; the first elastic piece and the second elastic piece are configured to be elastically deformable in the first direction; wherein at least one frame is in elastic sealing connection with the adjacent frame and / or the adjacent end plate through a first elastic piece, and each end plate is in elastic connection with the adjacent polar plate through a second elastic piece. The problems that the internal resistance of the battery is rapidly increased and the battery capacity and the large-current discharge capacity are reduced due to the falling of the positive electrode active layer can be avoided.

The invention discloses a tubular power type colloid lead-acid storage battery formation process, and relates to the technical field of lead-acid storage batteries. A one-time formation mode is adopted, the battery is connected into an electrolyte circulating flow system, sulfuric acid electrolyte containing phosphoric acid is poured, standing is carried out, a charging program is started, after multi-stage charging and discharging programs are carried out, discharging protection is carried out, the sulfuric acid electrolyte is discharged, colloid electrolyte is poured, charging is continued until battery gelling is carried out, and formation is finished. According to the invention, a complicated gel battery formation process flow is reduced into a one-time formation method, and the sulfuric acid electrolyte does not need to be subjected to high-low density switching in the production process or the sulfuric acid electrolyte is manually poured out one by one; a special charging and discharging process is adopted, so that the manufacturing energy consumption of the storage battery can be effectively reduced, the formation period and the charging multiple are close to those of a flooded tubular power battery, the production period of the gel battery is greatly shortened, efficient and stable conversion of active substances is realized, the initial performance and the service life of the gel battery are improved, and the manufacturing cost of the product is reduced.

A lead-acid battery 1 comprises: a battery case 20; an electricity storage element 30 and an electrolyte 35 which are housed in the battery case 20; a lid member 50 for sealing the upper surface of the battery case 20; and a vent plug 70 attached to the lid member 50. A plug body 71 of the vent plug 70 includes: a head portion 73 having an exhaust hole 73B; and a cylindrical portion 75 which protrudes downward from the head portion 73 and has an opening 76 at a tip. When the lead-acid battery 1 is in the upright or inverted position, the opening 76 at the cylinder tip of the cylindrical portion 75 of the vent plug 70 is positioned above a liquid surface of the electrolyte 35, and the opening 76 at the cylinder tip is closed by a wall.

The utility model discloses a storage battery wrapping workbench, and relates to the technical field of storage battery production, in particular to a storage battery wrapping workbench which comprises a panel, the bottom end of the panel is fixedly connected with a plurality of supporting legs distributed in a rectangular array, an upper plate is movably installed on the upper surface of the panel, a plurality of suction holes are formed in the inner side of the upper plate, a cavity is formed in the inner side of the panel, and a plurality of suction holes are formed in the inner side of the cavity. A limiting frame is movably installed on the inner side of the cavity, a plurality of through holes are formed in the inner side of the limiting frame, and a plurality of cushion blocks distributed in a rectangular array are fixedly connected to the upper surface of the limiting frame. Lead powder on the workbench can be sucked through the suction hole by the exhaust fan and collected by the dust collection box, the lead powder can be prevented from being sucked into the body by a worker, the plurality of bumps can be driven to rotate through the rotating rod by the turntable, so that the dredging rod can be driven to move up and down by the connecting column, the suction hole can be dredged, and the working efficiency is improved. And the suction hole is prevented from being blocked after long-term use.

To provide a separator for a lead-acid battery capable of having good bag-like workability and high battery safety, and a lead-acid battery including the same.SOLUTION: A separator for a liquid type lead-acid battery is provided having a porous base unit and a plurality of ribs provided on at least one surface of the porous base unit. The porous base unit has side end units arranged at both ends in a width direction and a center unit sandwiched between the side end units. Thickness of the side end unit is larger than that of the center unit. Relative element concentration of a nonmetallic element (S) is 0.01 atomic% or more and 0.5 atomic% or less when at least one surface of the base unit is measured by X-ray photoelectron spectroscopy.SELECTED DRAWING: None

The present application relates to the technical field of lead-acid battery preparation, and particularly relates to a green plate gel battery and a preparation process thereof, which comprises positive plate lead paste and negative plate lead paste, the positive plate lead paste comprises the following components: lead powder 100 parts, short fiber 0.08-0.12 parts, sulfuric acid 6.5-8.0 parts, and water 11-14 parts; the negative plate lead paste comprises the following components: lead powder 100 parts, sulfuric acid 5-6 parts, short fiber 0.05-0.1 parts, composite activated carbon 0.5-3 parts, sodium lignosulfonate 0.6-0.8 parts, barium sulfate 0.2-0.4 parts, humic acid 0.1-0.3 parts, and water 11-14 parts. The gel battery prepared by introducing the composite activated carbon into the negative plate lead paste and synergizing with the composite expansion agent system has a significant improvement in initial capacity and deep cycle life.

The invention discloses a storage battery based on a two-dimensional code traceability function. The storage battery comprises a storage battery body, an exclusive two-dimensional code identifier, a cloud database, a special management APP and an intelligent polishing tool, the exclusive two-dimensional code identifier is printed through acid and alkali resistant UV ink, covers the polycarbonate transparent wear-resistant coating and is permanently fixed on the battery cover of the storage battery body, and the color of the two-dimensional code and the battery cover form obvious visual contrast; the exclusive two-dimensional code identifier is associated with a unique identity identifier, and the unique identity identifier and storage battery full life cycle data are bound and stored in a cloud database. According to the method, the data reading efficiency is improved, the full-life-cycle data association rate is improved, manual one-by-one retrieval is not needed, complete data of the battery from production to operation and maintenance can be directly obtained through code scanning, errors of data recording and querying are reduced, meanwhile, physical coating and encryption dual protection is adopted for the two-dimensional code, the tampering rate is decreased to 0, and the anti-fake capacity is remarkably improved.

The application provides a battery protection mesh mounting system and method, by setting a taking and placing piece unit composed of a relatively up and down movable taking and placing piece assembly and a positioning assembly, the taking and placing piece unit inserts and takes the protection mesh and moves to a preset position in the battery mesh mounting groove, the positioning assembly first moves downward to press and position the protection mesh on the diaphragm plate, and then the taking and placing piece assembly moves upward to completely separate from the protection mesh, the active tool separation mode of the taking and placing piece assembly can ensure that the protection mesh can be completely separated, and the electric cylinder structure is adopted to drive the taking and placing piece unit to perform the lifting action, so that the stability is high, the action precision is high, the speed and stroke are adjustable, the work efficiency of the taking and placing piece is ensured, and the technical problems of low taking success rate, low taking success rate of the mesh peeling off from the needle, prevention of the mesh from being out of position and other problems affecting the mesh quality and utility in the prior art are solved.

The invention discloses a valve control type power storage battery electrolyte and a manufacturing method, the electrolyte is composed of the following components in parts by weight: 2-5 parts of sodium carboxymethyl cellulose, 2-5 parts of PEDOT: PSS, 0.5-1 part of manganese sulfate, 0.005-0.01 part of water-based carbon nanotubes, 2-5 parts of polyvinyl alcohol, 35-50 parts of sulfuric acid and 58-65 parts of deionized water, and all the components have a synergistic effect through precise proportioning; the preparation method comprises the steps of preparing a polyvinyl alcohol solution and a sodium carboxymethyl cellulose solution, dispersing conductive components, mixing to form gel, sulfating, adding manganese salt, curing, defoaming and the like, and process parameters are strictly controllable. Through component optimization and process innovation, electrolyte layering and negative electrode sulfation are effectively inhibited, interface impedance is reduced, the problem of uneven current distribution is solved, and grid corrosion and negative electrode self-discharge are reduced; tests show that the cycle index of the storage battery adopting the electrolyte is remarkably increased, the service life is prolonged, and the electrolyte is suitable for various power devices and standby power supply systems and has outstanding technical advantages and practical value.

The present disclosure relates to battery plates which are useful in optimizing the power and energy density of a batter assembly by having discrete active materials. The present disclosure relates to a battery plate having: a) a substrate having a first surface opposing a second surface; b) one or more active materials disposed on the first surface, second surface, or both the first surface and the second surface of the substrate; and wherein the one or more active materials include two or more discrete active material regions.

According to the storage battery with the detection chip provided by the utility model, the detection chip is additionally arranged on the battery cover of which the pole lug is arranged in the middle of the battery pole plate and the acid adding hole is biased, so that the detection chip and the temperature sensor are additionally arranged under the condition that the size of the lead storage battery is not influenced; temperature data of each plate group is collected through the temperature sensor, the detection chip collects the collected temperature data to the memory and then transmits the collected temperature data to the client, and real-time collection and remote monitoring of the battery temperature data are achieved.

The invention relates to the technical field of new energy automobile batteries, in particular to a traction lead-acid storage battery convenient to maintain, which comprises a battery main body and a battery opening outer cover mounted at a battery opening of the battery main body in a threaded manner, a battery opening inner cover is fixedly mounted at the center in the battery opening outer cover in a penetrating manner, and a floating ball floating on electrolyte is arranged in the battery opening inner cover. According to the traction lead-acid storage battery convenient to maintain, through cooperation of the floating ball and the folding assembly, the liquid level height of electrolyte can be visually observed without disassembling the outer cover, the maintenance time is shortened, and acid mist leakage or pollution caused by frequent cover opening is avoided; meanwhile, a dual-sealing design is adopted, electrolyte is prevented from shaking and overflowing through attached sealing of a flow guide plate and the floating ball, the overall sealing performance is enhanced through a spiral extrusion sealing mechanism, the acid liquor leakage risk is reduced, the floating ball can be fixed through a locking assembly after maintenance, the sealing performance is ensured, and the requirements for convenient maintenance and long-term sealing are met; therefore, the safety of the lead-acid storage battery for traction is enhanced.

The utility model discloses a shaping device for injection molding and cooling of a lead-acid storage battery shell, which relates to the technical field of shaping of the lead-acid storage battery shell and comprises a plurality of supporting pieces and a plurality of supporting strips, and clamping grooves are formed in the bottoms of the supporting strips along the length directions of the supporting strips. The supporting strips are connected to the top end of the side wall of the battery shell or the top end of the partition wall of the battery shell in a sleeved mode through the clamping grooves, the width of the clamping grooves is in interference fit with the width of the side wall of the battery shell or the width of the partition wall of the battery shell, and a set of supporting pieces are connected between the close side faces of the two supporting strips. During use, the left side wall, the right side wall, the front side wall and the rear side wall of the battery shell can be supported through the supporting pieces, the supporting ribs and the supporting strips, and meanwhile, the partition wall of the battery shell can be supported and limited, so that the battery shell can be effectively prevented from being sunken and deformed due to cooling shrinkage in the cooling process; the size precision and quality of the formed battery shell are ensured, and the quality of the battery shell is effectively improved.

An acid pot tool for formation of a valve-regulated lead-acid battery comprises an acid pot main body, and the middle part of the acid pot main body is provided with a cavity for accommodating electrolyte; a connector matched with a storage battery liquid injection hole is arranged at the bottom of the acid pot body, external threads matched with internal threads of the storage battery liquid injection hole are arranged on the periphery of the connector, and a rubber sealing ring is sleeved on the outer wall of the connector at the bottom of the external threads. An annular groove is independently arranged in an acid pot main body cavity close to the upper port of the acid pot main body, the outer annular wall of the annular groove is the inner wall of the acid pot main body, the top end of the inner annular wall of the annular groove is provided with a sealing plate, and the sealing plate is provided with small holes; the acid pot further comprises a rubber cap, the rubber cap is sleeved outside the inner ring wall of the annular groove through an opening in the bottom end, a gap between the outer wall of the rubber cap and the outer ring wall of the annular groove forms an annular exhaust gap, an upper port of the acid pot body is connected with a cover piece, and a gap reserved between the cover piece and the top end of the rubber cap forms an exhaust channel. The gas-liquid separator is compact in structure and reliable in sealing and has a gas-liquid separation function.

The application discloses a high-rate valve-regulated lead-acid battery and a preparation method thereof. The battery comprises a battery shell, a positive plate, a negative plate and an electrolyte arranged in the battery shell. The positive plate and the negative plate are both honeycomb lattice structure plates, and the positive plate is coated with a positive active material, and the negative plate is coated with a negative active material. The components of the positive active material include lead powder, graphite, sulfuric acid, nano lead dioxide and pure water. The components of the negative active material include lead powder, barium sulfate, sodium lignosulfonate, graphene composite additive and carbon black. The discharge rate of the high-rate valve-regulated lead-acid battery can reach 3-5C, and the discharge capacity retention rate is above 95% under the 1C discharge rate, which can meet the demand of 5G base stations, data centers and other fields for instantaneous large current and high power output.

Methods for operating a flooded electrolyte battery cell used in motive service to prevent the loss of water. When charging the cell, water in the electrolyte decomposes electrolytically to oxygen and hydrogen gases. The method includes catalytically recombining the oxygen and hydrogen gases to water vapor, inhibiting venting of the oxygen and hydrogen gases and water vapor from the cell, providing fluid communication between the catalyst and the electrolyte for the oxygen and hydrogen gases and water vapor, and hygroscopically absorbing the water vapor into the electrolyte. Devices and battery cells for carrying out the method are also provided.

The invention relates to the technical field of lead-carbon battery manufacturing, in particular to a high-specific-energy lead-carbon battery manufacturing method which comprises the following steps: S1, screening and pretreating a carbon material; s2, preparing lead carbon negative electrode paste; s3, preparing and casting a grid alloy; s4, plate coating and curing; s5, assembling a plate group; s6, packaging and welding a battery shell; s7, electrolyte filling and container formation are carried out; and S8, performing performance detection and aging. According to the scheme, when the lead-carbon negative electrode paste is prepared, firstly, strict pickling purification and high-strength ultrasonic dispersion treatment are carried out on a carbon material with a high specific surface area, so that impurities on the surface of carbon are thoroughly removed, a uniform and stable dispersion liquid is formed in water, and a solid foundation is laid for full combination of the carbon material and lead powder; then, a step-by-step gradient mixing strategy is adopted, the carbon dispersion liquid, dry powder and sulfuric acid are mixed in stages under the condition of multiple rotating speeds, precise temperature control is supplemented, it is ensured that active substances, carbon additives and fibers are evenly distributed, and agglomeration is effectively prevented.

This invention discloses an automatic ultrasonic welding device for lead-acid battery cover plates, including a conveying mechanism for transporting the battery. The cover-feeding mechanism includes a hopper for placing the cover plates, with a lifting component connected to the bottom of the hopper, which drives the cover plates in the hopper to move upwards. The cover-placing mechanism includes a transfer component A connected to the conveying mechanism, with a robotic arm A connected to the transfer component A, which drives the robotic arm A to move above the hopper or the conveying mechanism. The welding mechanism includes an ultrasonic welding device connected to a frame. A stop mechanism connected to the frame clamps the battery on the conveying mechanism. A translation mechanism includes a transfer component B connected to the frame, with a robotic arm B connected to the transfer component B. Compared with the prior art, this invention allows for automated and continuous cover plate placement during battery welding, improving work efficiency while reducing labor costs for enterprises.

The application discloses a medium-large dense battery automatic slot-entering mechanism and relates to the technical field of battery production. The medium-large dense battery automatic slot-entering mechanism comprises a belt conveyor and a transfer mechanism, further comprises a hydraulic lifting seat installed in the transfer mechanism, the bottom of the hydraulic lifting seat is fixedly connected with a clamping base, a plurality of groups of symmetrical hydraulic clamping pieces are installed in the clamping base, a pressure-stopping mechanism penetrates through the clamping base and is inserted into the top of the hydraulic clamping piece, an abutting piece is installed between each group of hydraulic clamping pieces, and the bottom of the abutting piece elastically abuts against the pressure-stopping mechanism. The symmetrical hydraulic clamping pieces are arranged, the battery is clamped, the whole is driven to ascend by the hydraulic lifting seat, the abutting piece is pressed down by the transfer mechanism at this time, the pressure-stopping mechanism is forced to elastically abut against the top of the hydraulic clamping piece, physical locking is formed, the risk of the clamping jaw moving back is eliminated, the pressure-stopping mechanism penetrates through the clamping base and is directly inserted into the clamping piece, and additional locking devices are omitted.

Disclosed herein are exemplary embodiments of improved electrode plate and separator assemblies (400) for lead acid batteries, improved lead acid cells or batteries incorporating the improved assemblies, systems or vehicles incorporating the improved assemblies (400) and / or batteries (100), and methods related thereto. The electrode plate (200, 201) may have a grid (202) of a stamped, cast, or expanded metal manufacturing process. The grid (202) may have a non-uniform application of active material (203). The separators (300) preferably provide a support structure for resisting or mitigating any plate warping or plate deflection.

A lead-acid battery 1 includes a battery case 10, electrode plates 30A and 30B accommodated in the battery case 10, an electrolytic solution U accommodated in the battery case 10, and a liquid stopper 70 attached to the battery case 10. The liquid stopper 70 includes a stopper body 71 of a cylindrical shape, a splash preventing body 90 located inside the stopper body, and a catalyst device 100 which promotes a reaction to produce water from gas generated by a charge-discharge reaction. The catalyst device 100 is either entirely or partially inside the stopper body and is located, in relation to the splash preventing body 90, below the splash preventing body 90.

A tool for automatically assembling an electric eye of a lead-acid storage battery comprises a battery conveying track, a vibration rotating disc, a mechanical arm, an electric eye hammer located over an electric eye hole and a position-adjustable Z-axis linear motion module, and the battery conveying track is used for conveying a battery; a battery positioning device is arranged on the battery conveying track; the vibration rotating disc is arranged on one side of the battery conveying track, and a battery electric eye is contained in the vibration rotating disc; the mechanical arm is used for grabbing an electric eye at a discharging opening of the vibration rotating disc and then positioning and placing the electric eye in an electric eye hole of a battery, and the discharging end of the vibration rotating disc faces one side of the mechanical arm; and the Z-axis linear motion module is used for driving the electric eye hammer to vertically lift a hammer electric eye. An electric eye hammer is arranged, so that the electric eye can be smoothly mounted in an electric eye hole, the electric eye is effectively ensured to be assembled in place, and meanwhile, the device is suitable for assembling various types of batteries.

The invention discloses a high-temperature-resistant maintenance-free lead-acid storage battery for starting. The lead-acid storage battery comprises a positive plate, a negative plate, a partition plate, electrolyte and a storage battery tank, the positive plate comprises a positive grid filled with positive lead plaster; the negative plate comprises a negative plate grid filled with negative lead plaster; the negative electrode lead paste is prepared by curing lead powder, a condensation polymer of beta-naphthol sulfonic acid and formaldehyde, lignin, barium sulfate, acetylene black, short fibers, a sulfuric acid aqueous solution and deionized water according to a ratio. The condensation polymer of beta-naphthol sulfonic acid and formaldehyde added in the negative electrode lead paste has low solubility in an electrolyte and strong oxidation resistance, reduces the volume of lead sulfate crystals generated by discharge, increases the porosity of a negative electrode active substance, inhibits the formation of large-particle metal lead in the charging process, delays the shrinkage of the negative electrode active substance, and improves the charging efficiency. Meanwhile, the hydrogen evolution overpotential is improved, and the water loss of the storage battery is inhibited.

The utility model relates to the technical field of batteries, in particular to a polar plate, a polar group structure and a lead-acid battery. The polar plate provided by the utility model comprises a grid, a top tab and a bottom tab, the grid comprises a rectangular frame, a plurality of transverse ribs and a plurality of first vertical ribs are arranged in the rectangular frame, and the rectangular frame is provided with a first side edge and a second side edge which are opposite to each other along a first direction. According to the utility model, the current density of the lower part of the polar plate can be improved through the arranged bottom tab, and the distance between every two adjacent transverse ribs is gradually reduced from the first side edge to the middle part of the grid and from the second side edge to the middle part of the grid, so that the contact area between active substances in the middle of the polar plate and the middle part of the grid can be increased; therefore, the utilization rate of active substances in the middle of the polar plate is improved, and the service life of the battery is prolonged.