721 results about "Positive current" patented technology

The invention relates to the technical field of batteries, in particular to a battery. Comprising a positive plate and electrolyte, the positive plate comprises a positive current collector and a coating positioned on the surface edge of at least one side of the positive current collector along the length direction; the coating comprises filling particles, and the filling particles comprise at least one of inorganic particles and nitrogen-containing particles; the electrolyte comprises non-fluorinated cyclic carbonate and fluorinated ethyl acetate; the non-fluorinated cyclic carbonate comprises propylene carbonate and optional ethylene carbonate; on the basis of the total mass of the electrolyte, the content ratio C1 of the non-fluorinated cyclic carbonate is smaller than or equal to 25%, the content ratio C11 of the propylene carbonate is 3.1%-24.9%, the content ratio C12 of the ethylene carbonate is 0%-5%, and the content ratio C2 of the fluorinated ethyl acetate is 20.2%-70%. The battery provided by the invention can improve the problem of lithium precipitation under low-temperature discharge, and has relatively good short-circuit safety performance and relatively low high-temperature gas production rate.

A dual path PLL provides excellent output phase stability over PVT variations, without implementing a high accuracy TDC. A digital integral path employs a binary phase detector, comparing the reference and feedback signals, and an integrator to generate an oscillator control input to lock the long-term output phase to the reference signal. An analog proportional path employs a linear (e.g., edge triggered) phase detector and a charge pump and filter to generate an oscillator control input to mitigate phase noise in the output signal. The feedback signal to the proportional path is delayed, which has the effect of increasing the width of phase error pulses, and moving the charge pump operating point away from the zero point where it generates both positive and negative currents, which are difficult to match. A second linear phase detector in the proportional path compensates for the increased phase error pulse width by comparing the delayed and non-delayed feedback signals, and generating pulses in the opposite direction.

The invention discloses a battery and a power utilization device, and belongs to the technical field of secondary batteries. The battery comprises a positive plate, the positive plate comprises a positive current collector and a positive active material layer, the positive active material layer comprises a positive active material and a lithium supplement agent, and the lithium supplement agent comprises an iron-containing lithium supplement agent; the ratio (set as a) of the characteristic peak area of Fe < 3 + > to the peak area of O1s in the hollow electric state in the XPS spectrum of the positive plate, the ratio (set as b) of the negative electrode discharge capacity to the positive electrode discharge capacity of the battery and the discharge curve end potential (set as cV) of the negative plate are adjusted, so that a * b * c is controlled within a suitable range, the gram capacity of the positive plate can be effectively improved, and the battery performance is improved. And meanwhile, the cycle performance of the battery is ensured.

Battery device comprising a thermal insulation element and at least two battery cells arranged along a first direction, wherein the battery cell comprises an electrode assembly and electrolyte solution, the electrode assembly comprising positive electrode plates and negative electrode plates, the positive electrode plate comprising positive current collectors and positive film layers arranged on at least one side of the positive current collectors, the positive film layer comprising lithium phosphate, wherein the negative electrode plate comprises negative current collectors and negative film layers arranged on at least one side of the negative current collector, the negative film layer comprising graphite particles. characterized in that the electrolyte solution comprises fluorosulfonylimide salt, wherein the mass fraction of the fluorosulfonylimide salt in the electrolyte solution is 2% to 12%; wherein the battery cell comprises two first surfaces which are opposite each other along the first direction, wherein the thermal insulation element covers at least one of the two first surfaces and the dimension of the thermal insulation element along the first direction is 0.3 mm to 5 mm.

The invention discloses a sodium secondary battery, electrolyte and electric equipment, the sodium secondary battery comprises a positive pole piece, electrolyte and a negative pole piece, the positive pole piece comprises a positive current collector and a positive active material layer arranged on at least one side of the positive current collector, and the negative pole piece comprises a negative active material layer arranged on at least one side of the negative current collector. The positive electrode active material layer comprises a first positive electrode active material layer and a second positive electrode active material layer which are sequentially stacked in the direction away from the positive electrode current collector, the first positive electrode active material layer comprises a first positive electrode active material, and the second positive electrode active material comprises a second positive electrode active material; the second positive electrode active material comprises Na4M3 (PO4) 2P2O7, and M comprises at least one of Fe, Co, Mn or Ni; the electrolyte includes a solvent including a linear ether and a cyclic ether. According to the sodium secondary battery, the generation of sodium dendrites can be reduced, and the cycle life is prolonged.

The invention provides a positive pole piece, an electrochemical device and an electronic device, the positive pole piece comprises a positive current collector, a positive active material layer and a coating, the coating is located on the surface and / or inside the positive active material layer, and the coating comprises an organic compound, the organic compound comprises at least one functional group of a cyano group, an isonitrile group, an azinyl group and an isocyanate group, the thickness of the coating is 0.3-3 [mu] m, and the ratio of the thickness of the coating to the thickness of the positive electrode active material layer is 1: (5-50). The positive pole piece provided by the invention can improve the thermal safety, the high-temperature cycle performance, the high-temperature storage expansion rate and the mechanical safety of the electrochemical device.

The invention relates to the technical field of lithium ion batteries, in particular to a lithium iron manganese phosphate battery and a preparation method thereof, and the lithium iron manganese phosphate battery comprises a positive pole piece and a negative pole piece; the positive pole piece comprises a positive current collector and a positive active material layer arranged on the surface of the positive current collector; the positive electrode active material layer comprises lithium manganese iron phosphate; the lithium manganese iron phosphate comprises LiMnxFe1-xPO4, and x is more than or equal to 0.4 and less than or equal to 0.9; the surface density of the positive electrode active material layer is 493.4-584.3 g / m < 2 >; the negative electrode plate comprises a negative electrode current collector, a first negative electrode active material layer arranged on the surface of the negative electrode current collector and a second negative electrode active material layer arranged on the surface of the first negative electrode active material layer; the first negative electrode active material layer comprises first graphite; in a Raman spectrogram of the first graphite, ID / IG is 0.05 to 0.15; the second negative electrode active material layer comprises second graphite; and in the Raman spectrogram of the second graphite, ID / IG is 0.4-0.65. The lithium manganese iron phosphate battery provided by the invention has significantly improved energy density and charge.

The invention belongs to the technical field of battery preparation, and particularly relates to a battery. The battery comprises a positive plate, the positive plate comprises a positive current collector and a positive active material layer arranged on at least one surface of the positive current collector, and the positive active material layer comprises a positive active material and a complex; the structural formula of the complex is MFn-CF3SO2Li, M is selected from B or P, and n is 3 or 5; the surface resistance of the positive plate is recorded as a, and the unit is m omega; in the XPS map of the positive plate, the proportion of the S2p peak area of the complex in the binding energy range of 165-180eV is recorded as b; a and b meet the relational expression 1, the complex is subjected to a decomposition reaction under the battery charging and discharging or heating condition, gases such as SO2 and CF4 are released, and a pore structure is formed in a positive active material layer when the gases escape, so that the lithium ion transmission rate is improved, the lithium supplement effect is achieved, and the fast charging performance and the cycle life of the battery are comprehensively improved on the premise of not influencing the electronic contact among active material particles.

The invention relates to the technical field of batteries, in particular to a positive plate and a battery, the positive plate comprises a positive current collector, a functional layer located on the surface of the positive current collector and a positive active material layer located on the surface of the functional layer; the functional layer comprises first lithium conducting particles, and the first lithium conducting particles comprise inorganic oxide particles and solid electrolyte materials coating the surfaces of the inorganic oxide particles; n positive active material particles are arranged on any cross section, perpendicular to the plane of the positive current collector, in the positive active material layer along the thickness direction of the positive current collector; the thickness of the functional layer is Dg, and the unit is mu m; n and Dg satisfy the relational expression: 0.6 < = N / Dg < = 40. By arranging the functional layer containing the first lithium conducting particles, a continuous transverse lithium conducting passage can be formed at the bottom of the active material layer by means of the solid electrolyte coating material of the first lithium conducting particles, the problem of lithium concentration balance among the active material particles at the bottom layer of the positive electrode is effectively solved, and the low-temperature performance of the lithium battery is improved.

The invention discloses a gradient triggering method for preventing battery short circuit, which comprises the following steps: S1, uniformly mixing early-warning thermal expansion microspheres, open-circuit thermal expansion microspheres and conductive carbon black, adding a water-based adhesive, and fully dispersing to obtain a turbid liquid; s2, coating a current collector with the turbid liquid obtained in the step S1, and then carrying out drying treatment; wherein the expansion temperature of the early-warning thermal expansion microspheres is 85-95 DEG C, the expansion multiple is 10-15, and the early-warning thermal expansion microspheres are used for increasing the internal resistance of the battery during expansion so as to carry out early warning; the expansion temperature of the open-circuit thermal expansion microspheres is 130-140 DEG C, the expansion multiple is 50-100 times, and the open-circuit thermal expansion microspheres are used for disconnecting direct contact between the positive electrode current collector and the negative electrode during expansion and cutting off electron transmission so as to avoid internal short circuit thermal runaway. The anode current collector prepared on the basis of the gradient trigger safety response mechanism for preventing the internal short circuit of the lithium battery has the characteristic that a micron-sized protective layer is in contact with a cathode when the internal short circuit occurs, so that the defects of other methods such as expensive equipment, complex working procedures and reduction of the energy density of the battery are overcome.

The utility model relates to the technical field of batteries, and provides a battery cell and a battery, and the battery cell comprises a positive plate, a diaphragm and a negative plate which are wound and stacked; the negative plate comprises a negative current collector and a negative active material layer located on the negative current collector, and a plurality of negative tabs protrude out of one side of the negative current collector and are laminated to form a negative tab structure; the positive plate comprises a positive current collector and positive active material layers, and the positive active material layers are arranged on two opposite sides of the positive current collector; the positive active material layer is provided with a first empty foil area and a second empty foil area, a first tab of the positive plate is positioned in the first empty foil area and connected with the positive current collector, and a second tab is positioned in the second empty foil area and connected with the positive current collector; and the first tab and the second tab are positioned on the two sides of the negative tab structure along the second direction. Through the arrangement, the bending space ratio of the first tab, the second tab and the negative tab at the top of the battery cell is reduced, the space ratio of the battery cell is reduced, and the energy density of the battery cell is improved.

Battery cell, characterized in that it comprises an electrode assembly and an electrolyte solution, wherein the electrode assembly comprises a positive electrode plate, a separating film and a negative electrode plate arranged one above the other, wherein the positive electrode plate comprises a positive current collector and a positive active material layer arranged on at least one side of the positive current collector, wherein the positive current collector comprises a positive current collector section and a positive electrode tab, the positive electrode tab being arranged at at least one end of the positive current collector section along the longitudinal direction of the electrode assembly, wherein the negative electrode plate comprises a negative current collector and a negative active material layer arranged on at least one side of the negative current collector.the negative current collector comprises a negative current collector section and a negative electrode tab, wherein the negative electrode tab is arranged at at least one end of the negative current collector section along the longitudinal direction of the electrode assembly; , wherein the positive active material layer comprises positive active material, the positive active material comprises lithium phosphate with olive stone structure; wherein the positive active material layer has a size of 300 mm to 950 mm along the longitudinal direction of the electrode assembly; wherein the size of the negative active material layer along the longitudinal direction of the electrode assembly is larger than the size of the positive active material layer, the difference between the size of the negative active material layer and the size of the positive active material layer is OH1, wherein OH1 is greater than 1 mm and less than 5 mm, wherein the size of the negative active material layer along the transverse direction of the electrode assembly is larger than the size of the positive active material layer, the difference between the size of the negative active material layer and the size of the positive active material layer is OH2, wherein OH2 is greater than 1 mm and less than or equal to 4 mm; wherein the electrolyte solution in question comprises a solvent and a lithium-containing electrolyte salt, wherein the solvent comprises a carboxylic acid ester solvent and the lithium-containing electrolyte salt comprises a fluorosulfonylimide lithium salt, wherein the mass fraction of the carboxylic acid ester solvent, based on the total mass of the electrolyte solution, is 8% to 57% and the mass fraction of the fluorosulfonylimide lithium salt is 3% to 8%.

The invention discloses a current measuring circuit based on a quadrupole mass spectrometer, and the circuit comprises an input module which is used for receiving a current signal from the quadrupole mass spectrometer; the current detection module is used for carrying out current measurement on the current signal; wherein the current measurement module comprises a positive current measurement unit and a negative current measurement unit, the positive current measurement unit is used for measuring the positive current of the quadrupole mass spectrometer, and the negative current measurement unit is used for measuring the negative current of the quadrupole mass spectrometer; according to the current measurement circuit, small current linear amplification and large current logarithmic amplification are realized through the current measurement module, so that a high-range measurement effect is achieved, fA level-uA level current measurement can be realized, and meanwhile, automatic range switching is realized through circuit characteristics; and the cost is about one fiftieth of that of a reed switch range switching scheme.

The invention relates to the technical field of visual defect detection, in particular to a carbon-coated aluminum foil appearance quality defect detection method for a lithium ion battery, and the method comprises the steps: collecting a to-be-detected carbon-coated aluminum foil image applied to a lithium ion battery positive electrode current collector; determining a first feature, a second feature and a third feature of each pixel point; dividing pixel points in the to-be-detected carbon-coated aluminum foil image into various types; determining the circular conformity of each type of pixel points, and obtaining circular pixel points in all types of pixel points; for the non-circular pixel points, determining the ellipse conformity of each type of pixel points, and obtaining ellipse pixel points in the non-circular pixel points; and based on the circular conformity and the elliptical conformity, respectively carrying out image enhancement on the circular pixel points and the elliptical pixel points, and detecting the material throwing defect in the enhanced to-be-detected carbon-coated aluminum foil image by utilizing the classification model. The accuracy of appearance quality detection of the carbon-coated aluminum foil is improved.

The lithium ion battery comprises a positive plate, a negative plate and an electrolyte, the positive plate comprises a positive current collector and a positive active material layer arranged on at least one side surface of the positive current collector, the positive active material layer comprises a positive active material, and the positive active material comprises spinel lithium nickel manganese oxide; the ratio of the ordered crystallization peak intensity to the disordered crystallization peak intensity in an X-ray diffraction pattern of the positive electrode active material is A; the electrolyte comprises an additive, the additive comprises a sulfonate compound, and the mass percentage content of the sulfonate compound in the electrolyte is B%; and the lithium ion battery satisfies 0.7 < = B / A < = 5. According to the scheme provided by the invention, the film forming effect of the sulfonate compound can adapt to the structural state of the positive electrode active material through the cooperation of the internal and external electrolyte components of the positive electrode active material, so that the accurate repair of the performance defects of the battery is realized, and the performance of the battery is effectively improved.

The invention belongs to the field of batteries, and particularly relates to a positive plate, a lithium battery and a preparation method thereof. Comprising a positive current collector and an active coating coated on the surface of the positive current collector, the active coating comprises a first coating close to the current collector and a second coating far away from the current collector; the first positive electrode active material is a mixture of monocrystal lithium manganese iron phosphate and a lithium-rich manganese-based material, and the second positive electrode active material is aggregate lithium manganese iron phosphate. The positive plate adopts a double-layer coating design, the first coating close to one side of the current collector is made of high-manganese lithium manganese iron phosphate in a nano small particle form, the second coating far away from the current collector is made of a low-manganese lithium manganese iron phosphate material in an aggregate form, and a gradient manganese distribution design with high manganese in the inner layer and low manganese in the outer layer is constructed; the manganese dissolution risk can be effectively reduced, and the cycle performance is improved. And meanwhile, the energy density of the battery can also be improved by using the high-manganese-content lithium manganese iron phosphate.

The invention provides a lithium ion battery and a preparation method thereof, and relates to the technical field of lithium ion batteries. The lithium ion battery comprises a positive plate, a negative plate, a diaphragm and electrolyte, the positive plate comprises positive slurry and a positive current collector; the positive electrode slurry comprises doped lithium iron phosphate, and the preparation method of the doped lithium iron phosphate comprises the following steps: S1, mixing, drying and calcining an iron source, a phosphorus source, a lithium source and a carbon source in a solvent to obtain a precursor; s2, adding a metal source and a fluorine source into the precursor, and mixing to obtain a mixture; and S3, calcining the mixture to obtain the doped lithium iron phosphate. According to the lithium ion battery provided by the invention, the energy density is considered, and meanwhile, long-circulation storage is realized.

The invention relates to the technical field of batteries, and discloses a secondary battery and electric equipment.The secondary battery comprises a positive plate, a negative plate, a diaphragm and electrolyte, the positive plate comprises a positive current collector and a positive active layer coating at least one side surface of the positive current collector, and the positive active layer comprises a positive active material; the positive electrode active material comprises a nickel-cobalt-manganese ternary material and lithium-containing phosphate; the electrolyte comprises a solvent, a lithium salt and an additive, the solvent comprises a first solvent and a second solvent, the mass ratio of the second solvent in the electrolyte is a, the mass ratio of the first solvent in the electrolyte is b, and the value of a / b is 0.4-5; the additive comprises a phosphorus-containing additive, the mass ratio of the phosphorus-containing additive in the electrolyte is c, and c is larger than or equal to 0.01% and smaller than or equal to 1.5%.

The invention discloses a high-power lithium iron phosphate battery and a preparation method thereof. The high-power lithium iron phosphate battery comprises a positive plate, a negative plate, a diaphragm and electrolyte. The positive plate comprises a positive material layer and a positive current collector; the negative plate comprises a negative electrode material layer and a negative electrode current collector; the diaphragm is coated with an adhesive layer composed of ceramic and polyvinylidene fluoride, and the porosity of the diaphragm is 45%-50%; the electrolyte comprises a lithium salt, an organic solvent and an additive, and the mass ratio of the lithium salt to the organic solvent to the additive is (13-18): (75-80): (3-8). By optimizing the positive plate, the negative plate, the diaphragm and the electrolyte, the prepared high-power lithium iron phosphate battery has high reliability, long cycle life and wide temperature range under high-power discharge.

A battery cell, a battery device, and an electrical appliance belong to the field of battery technology. The battery cell includes: a positive electrode, a negative electrode, an electrolyte, and a packaging bag; the positive electrode includes a positive current collector, a positive electrode film, and an insulating layer; the positive current collector includes a positive electrode body and a positive electrode tab; the positive electrode body includes a coating area and a transition area; along a first direction, the transition area is located at at least one end of the coating area; the positive electrode film is disposed on at least one side surface of the coating area; the insulating layer includes a first portion disposed on at least one side surface of the transition area; the negative electrode includes a negative electrode film; along the first direction, the edge of the negative electrode film extends beyond the edge of the first portion near the positive electrode tab; a chamfered structure is provided at the connection between the first and second sides of the negative electrode; the electrolyte has an ionic conductivity of 8.5 mS / cm to 20 mS / cm, which can improve the reliability and cycle performance of the battery cell.

The invention provides a secondary battery and an electric device. The secondary battery comprises a positive pole piece, a negative pole piece and an electrolyte, the positive pole piece comprises a positive current collector and a positive film layer arranged on at least one side of the positive current collector, the positive film layer comprises a first type of particles and a second type of particles, and the first type of particles and the second type of particles comprise a lithium-containing transition metal phosphate material; the molar ratio of Mn in the first type of particles is larger than or equal to 0.5, the primary particle size of the second type of particles is larger than the average value of the primary particle size of the first type of particles, the average value of the molar ratio of Mn in the second type of particles is smaller than the average value of the molar ratio of Mn in the first type of particles, and the molar ratio of Mn refers to the ratio of the molar number of Mn to the total molar number of Mn and Fe.

The invention provides a secondary battery and a power utilization device, the secondary battery comprises a positive pole piece, a negative pole piece and an electrolyte, the positive pole piece comprises a positive current collector and a positive film layer which is arranged on at least one side of the positive current collector and comprises a positive active material; the positive electrode active material comprises a lithium iron phosphate material inner core and a carbon shell layer at least partially coating the outer surface of the inner core, and in a Raman spectrum of the positive electrode active material, the ratio Id / Ig of the peak intensity Id of a D peak in the Raman shift range of 1350 + / -50 cm <-1 > to the peak intensity Ig of a G peak in the Raman shift range of 1580 + / -50 cm <-1 > is 0.2-1.5; the negative electrode piece comprises a negative electrode current collector and a negative electrode film layer arranged on at least one side of the negative electrode current collector, and when the state of charge of the secondary battery is 100% or the voltage of the secondary battery is 3.65 V, the heat release Q of the negative electrode film layer in the electrolyte is larger than or equal to 250 J / g and smaller than or equal to 600 J / g.

The invention provides a composite positive pole piece, a preparation method thereof and a lithium ion battery. The composite positive pole piece comprises a positive current collector, and a first active material layer, a second active material layer and a third active material layer which are sequentially stacked on the surface of at least one side of the positive current collector, the active materials in the first active material layer and the third active material layer independently include a phosphate-based positive electrode material, and the active material in the second active material layer includes a nickel-based positive electrode material. According to the invention, the phosphate positive electrode material active layer, the nickel-based positive electrode material active layer and the phosphate positive electrode material active layer are sequentially arranged on the current collector and have a composite synergistic effect, so that the positive electrode plate has both energy density and safety performance. Through the sandwich electrode design of the three composite active substance layers, the high energy density characteristic of a ternary material is reserved, and meanwhile, the ternary active substance layers are coated with the high-stability phosphate active substance layers, so that the electrode also has the good safety characteristic.

The invention relates to the technical field of batteries, in particular to a positive plate and a preparation method thereof, a battery and electric equipment. The positive plate comprises a positive current collector and a positive active material layer arranged on one side of the positive current collector, the positive active material layer comprises a first active material layer and a second active material layer which are arranged in a stacked mode, the first active material layer is located between the second active material layer and the positive current collector, the first active material layer comprises LiMnx1Fey1PO4 and LiNia1Cob1Mc1O2, x1 + y1 = 1, a1 + b1 + c1 = 1, and the second active material layer is located between the first active material layer and the positive current collector. M comprises at least one of Mn, Al, Zr and Ti; the second active material layer comprises LiMnx2Fey2PO4 and LiNia2Cob2Mc2O2, x < 2 > + y < 2 > = 1, a < 2 > + b < 2 > + c < 2 > = 1, and M'comprises at least one of Mn, Al, Zr and Ti; the ratio of the mass content of Fe to the mass content of Co in the first active material layer is different from the ratio of the mass content of Fe to the mass content of Co in the second active material layer. According to the positive plate, micro-interface polarization can be improved, and the risk of local lithium precipitation caused by uneven charge distribution is reduced.

The utility model provides a secondary battery, a battery pack and an electronic device. The secondary battery includes: a case; the electrode assembly is accommodated in the shell and is formed by laminating a positive plate, a diaphragm and a negative plate; at least one surface of a positive current collector of the positive plate is covered with a positive active material layer, and at least one surface of a negative current collector of the negative plate is covered with a negative active material layer; in the preset direction, the positive electrode active material layer comprises a positive electrode straight area and a positive electrode thinned area which are connected, and the negative electrode active material layer comprises a negative electrode straight area and a negative electrode thinned area which are connected; in the preset direction, the edge, close to the first end, of the negative electrode straight area exceeds the edge, close to the first end, of the positive electrode straight area opposite to the negative electrode straight area, and the edge, close to the first end, of the positive electrode thinned area does not exceed the edge, close to the first end, of the negative electrode thinned area, so that the lithium precipitation probability of the thinned area is reduced.

A secondary battery includes a positive electrode having a covered portion and a positive active material non-covered portion on a strip-shaped positive electrode foil, the covered portion being covered with a positive active material layer, and a negative electrode having a covered portion and a first negative active material non-covered portion on a strip-shaped negative electrode foil, the covered portion being covered with a negative active material layer, the positive active material non-covered portion being joined to a positive current collector plate at one end of an electrode roll body, the first negative active material non-covered portion being joined to a negative current collector plate at the other end of the electrode roll body, the electrode roll body having a flat surface formed by bending and overlapping a center axis of a structure wound in either one or both of the positive active material non-covered portion and the first negative active material non-covered portion, and a groove formed in the flat surface, and the negative electrode having a second negative active material non-covered portion at an end of a lengthwise winding start side.

The invention provides a secondary battery and an electronic device. The secondary battery comprises a positive pole piece and electrolyte, the positive pole piece comprises a positive current collector, a positive material layer and a protective layer, the positive material layer and the protective layer are both located on at least one surface of the positive current collector, the positive current collector comprises a main body area and a tab area in the width direction of the positive current collector, the positive material layer is arranged in the main body area, and the tab area is arranged in the main body area. The protective layer is arranged in the tab area; the area proportion of the protective layer covering the tab region is S, 0.6 < = S < = 1, and the contact angle theta between the protective layer and the electrolyte is greater than 90 degrees and less than or equal to 165 degrees. The secondary battery provided by the invention has good safety performance.

In accordance with an embodiment, a method of measuring a load current flowing through a current measurement resistor coupled between a source node and a load node includes: measuring a first voltage across a replica resistor when a first end of the replica resistor is coupled to the source node and a second end of the replica resistor is coupled to a reference current source; measuring a second voltage across the replica resistor when the second end of the replica resistor is coupled to the source node and the first end of the replica resistor is coupled to the reference current source; measure a third voltage across the current sensing resistor; and calculating a corrected current measurement of the load current based on the measured first voltage, the measured second voltage and the measured third voltage.

A Prussian blue sodium-ion battery and its preparation method are disclosed, belonging to the field of sodium-ion battery technology. The specific solution is as follows: A Prussian blue sodium-ion battery includes a positive electrode and a negative electrode. The positive electrode includes a positive current collector and a positive active material layer on the surface of the current collector containing positive active material. The water content of the positive active material layer is 0-90 μg / g. Only a portion of the voltage plateau of the positive active material functions during battery charging and discharging. This invention fundamentally solves the problem of battery swelling and electrical performance degradation caused by water in the positive active material. Furthermore, by controlling the insertion / extraction depth of sodium ions in the Prussian blue positive electrode material, the damage caused to the structure of the Prussian blue positive electrode material by deep insertion / extraction of sodium ions during battery charging and discharging is reduced, thereby achieving long-cycle performance of the sodium-ion battery while maintaining a high specific capacity of the Prussian blue positive electrode material.

The invention relates to the technical field of sodium ion batteries, and particularly discloses a sodium ion battery positive plate and a preparation method thereof, the positive plate comprises a positive current collector and at least three active material coating layers coated on the surface of the positive current collector; each active material coating layer comprises a layered oxide positive electrode material and a polyanionic compound positive electrode material; in the at least three active substance coating layers, the content of the layered oxide positive electrode material and the content of the polyanionic compound positive electrode material are in uniform gradient distribution, and the content of the layered oxide positive electrode material is gradually increased from a position close to a tab of the sodium ion battery to a position far away from the tab; and the content of the polyanionic compound positive electrode material is gradually reduced from the position close to the tab to the position far away from the tab. According to the invention, by controlling the proportion of the oxide and the polyanionic compound in the plurality of positive active material coating layers from the tab position to the non-tab position, the sodium ion battery is more stable in structure and better in cycle performance in the charge-discharge process.