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CN-122025430-A - Low-inductance high-current winding type super capacitor electrode structure

CN122025430ACN 122025430 ACN122025430 ACN 122025430ACN-122025430-A

Abstract

The invention discloses a low-inductance high-current winding type super capacitor electrode structure and a preparation method thereof, and belongs to the technical field of super capacitors. The invention comprises an anode electrode unit, a cathode electrode unit and a porous diaphragm, wherein the anode electrode unit, the cathode electrode unit and the porous diaphragm are overlapped and then are wound in a staggered way to form a capacitor core body, the anode electrode unit and the cathode electrode unit are all ultrathin metal current collectors through single-sided vacuum evaporation of an insulating base film, the back surface of the base film is synchronously evaporated with a discontinuous aluminum metal grid stress compensation layer in a furnace, the surface of the current collector is coated with an active carbon/graphite composite active layer, the active layer adopts a three-sided closed-loop U-shaped PI insulation edge sealing design, only a single end is controllably exposed, two end surfaces of the wound core body are respectively exposed with the edges of the unipolar current collectors and the active layer, and the whole current collecting electrode is formed through end surface zinc-tin alloy spraying, and meanwhile, a modularized linear scaling full-capacity section preparation process is provided in a matched mode. Through the collaborative innovation of the structure and the process, the ultra-large capacity full-scene application from milli-scale micro-scale to ten-thousand-scale ultra-large capacity can be compatible, the ultra-low internal resistance, the ultra-low parasitic inductance, the high volume utilization rate and the high mass production yield are realized, the ultra-large current pulse scene from the physical networking sensor to the electromagnetic ejection is perfectly adapted, all the preparation procedures are completely adapted to the existing mature production line in China, the low-cost mass production floor can be realized, and the long-term stable technical protection is provided for the ultra-capacitor full-scene application.

Inventors

  • Request for anonymity

Assignees

  • 广西钦州市华源电子有限公司

Dates

Publication Date
20260512
Application Date
20260324

Claims (11)

  1. 1. The low-inductance high-current winding type super capacitor electrode structure is characterized by comprising a positive electrode unit, a negative electrode unit and a porous isolating film, wherein the positive electrode unit, the porous isolating film and the negative electrode unit are sequentially overlapped and then wound in a staggered manner to form a capacitor core body; the positive electrode unit comprises a first insulating base film, wherein a positive aluminum current collector is evaporated on a first surface of the first insulating base film in a vacuum manner, a discontinuous aluminum metal grid stress compensation layer is evaporated on a second surface of the first insulating base film, a positive active carbon/graphite composite active layer is coated on the surface of the positive aluminum current collector, U-shaped PI insulating sealing edges are coated on the non-exposed end and two length direction side edges of the positive active carbon/graphite composite active layer, the exposed end of the positive active carbon/graphite composite active layer is level with the end part of the positive aluminum current collector, the negative electrode unit comprises a second insulating base film, a negative copper current collector is evaporated on the first surface of the second insulating base film in a vacuum manner, a discontinuous aluminum metal grid stress compensation layer is evaporated on the second surface of the second insulating base film, a negative active carbon/graphite composite active layer is coated on the surface of the negative copper current collector, U-shaped PI insulating sealing edges are coated on the non-exposed end and two length direction side edges of the negative active carbon/graphite composite active layer, the negative active carbon/graphite composite active layer and the exposed end part of the negative active carbon/graphite composite active layer are level with the end part of the positive active carbon/graphite composite active layer, the positive active carbon/graphite active layer and the exposed end of the positive active carbon/graphite active layer and the negative electrode unit are opposite to the positive active carbon/negative electrode active layer and the positive active electrode unit respectively, the positive active electrode unit and the negative electrode active electrode unit are in turn, and the positive active carbon active layer and negative electrode active layer and the active electrode unit are opposite to the active layer and active layer, the offset of dislocation is 1-5mm, the width of the porous diaphragm is larger than that of the positive electrode/negative electrode active carbon/graphite composite active layer, the coating area of the positive electrode active layer and the negative electrode active layer is completely covered, two end faces of the wound capacitor core body only expose the edges of the monopole current collector and the active layer respectively, and zinc-tin alloy metal conductive layers are sprayed on the two end faces to form the whole current collecting electrode.
  2. 2. The low-inductance high-current winding type super capacitor electrode structure according to claim 1, wherein the discontinuous aluminum metal grid stress compensation layer and the current collector on the corresponding side are prepared by adopting a synchronous evaporation process in a same furnace, the thickness is 30-150nm, and the thickness deviation from the corresponding current collector is less than or equal to 10%.
  3. 3. The low-inductance and high-current winding type super capacitor electrode structure according to claim 1, wherein the first insulating base film and the second insulating base film are mutually independent electrolyte-resistant fluoride modified PET (polyethylene terephthalate) films or PP (polypropylene) films, the thickness of the base film is 4-15 microns, and the thicknesses of the anode aluminum current collector and the cathode copper current collector are 0.3-5 microns.
  4. 4. The low-inductance and high-current winding type super capacitor electrode structure according to claim 1 is characterized in that the U-shaped PI insulating sealing edge is of a three-face closed-loop structure, the sealing edge width is 1-5mm, the sealing edge thickness is consistent with the thickness of a corresponding active carbon/graphite composite active layer, the exposed length of the positive electrode/negative electrode active carbon/graphite composite active layer is 0.2-1mm, and the thickness is 30-150 mu m.
  5. 5. The low-inductance high-current winding type super capacitor electrode structure according to claim 1, wherein the porous diaphragm is a PP porous non-woven fabric or glass fiber diaphragm, the thickness is 15-40 μm, and the width of the diaphragm is 1-4mm larger than the width of the positive/negative electrode active carbon/graphite composite active layer.
  6. 6. The low-inductance high-current winding type super capacitor electrode structure according to claim 1, wherein the thickness of the zinc-tin alloy metal conductive layer is 0.1-1mm, and the edges of the current collector and the active layer exposed from the corresponding end surfaces are completely covered.
  7. 7. The low inductance high current winding type super capacitor electrode structure according to claim 1, wherein the first insulating base film and the second insulating base film are the same piece of common insulating base film, the positive electrode aluminum current collector is vacuum deposited on the upper surface of the common insulating base film, the negative electrode copper current collector is vacuum deposited on the lower surface of the common insulating base film, and the positive electrode aluminum current collector and the negative electrode copper current collector are arranged in a staggered manner on the front surface and the back surface of the common insulating base film.
  8. 8. The low inductance, high current winding type supercapacitor electrode structure according to claim 7, wherein the common insulating base film has discontinuous aluminum metal mesh stress compensation layers having the same thickness as the corresponding current collector deposited on both the front and back surfaces of the common insulating base film in the blank areas not covered by the current collector.
  9. 9. The low-inductance high-current winding type super capacitor electrode structure according to claim 7, wherein the common insulating base film is an electrolyte-resistant fluoride modified PET film or PP film, and the thickness is 8-15 μm.
  10. 10. The preparation method of the low-inductance high-current winding type super-capacitor electrode structure is characterized by comprising the following steps of: S1, preprocessing a base film, namely selecting 2 electrolyte fluoride-resistant modified PET/PP films with corresponding thickness according to target capacity, respectively serving as a positive base film and a negative base film, performing argon plasma activation treatment on a surface to be evaporated of the base film, and improving surface energy; s2, vacuum evaporation of a current collector, namely evaporating an aluminum current collector with corresponding thickness on the surface of a positive base film and evaporating a copper current collector with corresponding thickness on the surface of a negative base film by a resistance evaporation coating process in a high vacuum environment of 10 < -3 > to 10 < - 4 > Pa, and simultaneously evaporating a discontinuous aluminum metal grid stress compensation layer with the thickness of 30 nm to 150nm on a non-evaporation surface of the base film in the same furnace; S3, coating an insulating edge seal, namely coating a U-shaped PI insulating edge seal with a corresponding width on the surface of a current collector through a slit coating process, and forming an insulating flange after UV light curing; s4, coating an active layer, namely coating an active carbon/graphite composite active layer with corresponding thickness in an area surrounded by an insulating edge seal, and drying and curing at a low temperature of 60-80 ℃; s5, slitting and rolling, namely slitting the coated pole piece into preset widths, compacting the active layer through 2-3 times of low-pressure rolling, and controlling the compaction density to be 0.5-0.7g/cm < 3 >; S6, staggered winding, namely sequentially staggered overlapping the positive electrode, the porous diaphragm and the negative electrode, wherein the exposed end of the positive electrode and the exposed end of the negative electrode face opposite directions, winding a capacitor core body with corresponding size by a low-tension winding machine, and respectively exposing the edges of the monopole current collector and the active layer at two end surfaces of the core body; s7, performing metal spraying and current collecting, namely performing numerical control on two end surfaces of the core body to be Cheng Damo, leveling, adopting a process of fractional thin spraying and interval air cooling, and spraying zinc-tin alloy metal conductive layers with corresponding thickness on the two end surfaces through electric arc spraying to form a whole-surface current collecting electrode; and S8, filling and packaging, namely performing vacuum filling, high-temperature negative pressure infiltration, stepwise small-current fluidization and sealing packaging on the core body to finish the preparation of the super capacitor with corresponding capacity.
  11. 11. The preparation method of the low-inductance high-current winding type super-capacitor electrode structure is characterized by comprising the following steps of: S1, preprocessing a base film, namely selecting 1 electrolyte-resistant fluoride modified PET/PP film with corresponding thickness as a common base film according to target capacity, and synchronously performing argon plasma activation processing on the front side and the back side of the base film; S2, double-sided dislocation vacuum evaporation, namely evaporating anode aluminum current collectors with corresponding thickness in dislocation arrangement on the upper surface of a base film and cathode copper current collectors with corresponding thickness in dislocation arrangement on the lower surface of the base film by a double-source synchronous evaporation coating process under a high vacuum environment of 10 < -3 > to 10 < - 4 > Pa, and simultaneously evaporating discontinuous aluminum metal grid stress compensation layers with the same thickness as the current collectors in the same furnace synchronously in a blank area where the current collectors are not covered; S3, coating double-sided insulating sealing edges, namely synchronously coating mirror image U-shaped PI insulating sealing edges with corresponding widths on the front side and the back side of the base film through an air cushion suspension double-sided coating machine, and forming insulating flanges after UV light curing; s4, coating double-sided active layers, namely synchronously coating active carbon/graphite composite active layers with corresponding thickness on the front side and the back side of the base film by taking an insulating edge seal as a positioning reference, and carrying out double-sided synchronous infrared heating curing; S5, slitting and rolling, namely slitting the coated composite pole piece into preset widths, and compacting the active layer through double-sided synchronous low-pressure rolling; s6, winding and forming, namely winding a capacitor core body with corresponding size through a low-tension winding machine after the composite electrode and the porous diaphragm are overlapped, wherein two end surfaces of the core body are respectively exposed out of the edges of the monopole current collector and the active layer; S7, performing metal spraying and current collecting, namely performing numerical control on two end surfaces of the core body to be Cheng Damo and smooth, and performing electric arc spraying on zinc-tin alloy metal conductive layers with corresponding thickness by adopting a process of fractional thin spraying and interval air cooling to form a whole-surface current collecting electrode; And S8, liquid injection and packaging, namely performing vacuum liquid injection, high-temperature negative pressure infiltration, stepped formation and sealing packaging on the core body to finish the preparation of the super capacitor with corresponding capacity.

Description

Low-inductance high-current winding type super capacitor electrode structure Technical Field The invention belongs to the technical field of supercapacitors, and particularly relates to a low-inductance high-current winding type supercapacitor electrode structure adapting to a full-capacity section. Background The double-layer super capacitor is widely applied to full scenes from miniature internet of things sensors, consumer electronics fast charging, electromagnetic ejection, vehicle-mounted start-stop, power grid energy storage and the like to cover ultra-wide capacity ranges from millifarads to ten thousand farads by virtue of the characteristics of fast charging and discharging speed, long cycle life and high power density. The existing winding type super capacitor structure has core pain points which cannot be solved in different capacity sections. The miniature small-capacity scene is that a 10-20 mu m thick copper/aluminum foil current collector and miniature tab welding structure is adopted, the non-energy storage dead volume of the thick current collector and the tab is more than 30%, the capacity is extremely low under the same volume, meanwhile, the miniature tab welding difficulty is extremely high, the false welding and desoldering rate is more than 30%, the mass production yield is less than 70%, and the internal resistance and parasitic inductance caused by the tab are increased rapidly, so that pulse discharge cannot be realized. The conventional structure has complicated procedures, the alignment winding precision of the bipolar plate is difficult to control, the bridging short circuit of the anode and the cathode is easy to occur, the mass production yield is generally lower than 90%, the single-point confluence of the polar lugs leads to large contact internal resistance, the parasitic inductance is generally hundreds of nH, and the high-current requirements of the scenes such as a high-frequency pulse power supply, a small-sized electromagnetic ejection model and the like cannot be adapted. The high-capacity high-power scene is that a multi-lug welding structure is adopted, the current carrying capacity is limited by the number of the lugs, at most, only 4-6 lugs can be arranged, the local current density of the lug welding spots is fluctuated under thousands of amperes of current, the heating, ablation and desoldering are extremely easy, the multi-lug welding process is complex, the mass production efficiency is low, the reject ratio is over 15 percent, the metal fatigue is easy to occur during long-term large-current circulation, and the cycle life is greatly shortened. Disclosure of Invention The invention aims to overcome the defects of the prior art, and provides a low-inductance high-current winding type super-capacitor electrode structure, wherein a vacuum evaporation ultrathin current collector is used for replacing a traditional thick metal foil, a discontinuous stress compensation layer on the back of a base film, a three-side closed-loop U-shaped insulating sealing edge for preventing short circuit, controllable exposure reinforcement of a monopole active layer, misplaced winding and metal spraying current collection on the whole end face are matched, so that a set of structure is compatible with millimethod-level to ten thousand-method-level full-capacity section application, and core pain points with high internal resistance, large parasitic inductance, low volume utilization rate, low mass production yield and poor full scene suitability in the prior art are solved. Technical proposal In order to achieve the above purpose, the present invention provides the following technical solutions: The low-inductance high-current winding type super capacitor electrode structure comprises a positive electrode unit, a negative electrode unit and a porous diaphragm, wherein the positive electrode unit, the porous diaphragm and the negative electrode unit are sequentially overlapped and then wound in a staggered manner to form a capacitor core; The positive electrode unit comprises a first insulating base film, a positive aluminum current collector is evaporated on a first surface of the first insulating base film in a vacuum manner, and a discontinuous aluminum metal grid stress compensation layer is evaporated on a second surface of the first insulating base film; The surface of the positive aluminum current collector is coated with a positive active carbon/graphite composite active layer, the non-exposed end and two longitudinal side edges of the positive active carbon/graphite composite active layer are coated with U-shaped PI insulating sealing edges, and the exposed end of the positive active carbon/graphite composite active layer is flush with the end part of the positive aluminum current collector; The negative electrode unit comprises a second insulating base film, a negative copper current collector is evaporated on the first surface of the second insulating base film in a vacu