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CN-122025434-A - Oxide composite electrolyte high-voltage energy storage device and preparation method thereof

CN122025434ACN 122025434 ACN122025434 ACN 122025434ACN-122025434-A

Abstract

The invention discloses an oxide composite electrolyte high-voltage energy storage device and a preparation method thereof, and belongs to the technical field of electrochemical energy storage devices. The energy storage device adopts Nb doped LLZO oxide-polymer composite electrolyte, thoroughly solves the brittleness problem of pure ceramic solid electrolyte, improves the single unit withstand voltage to above 20V, and directly realizes high-voltage direct-out of above 1000V by forming a 50-100-layer internal series structure through alternate lamination of double-side heteropolar composite electrodes and diaphragms. The preparation method adopts a vacuum infiltration and gradient hot-pressing process, perfectly multiplexes the whole set of core processes of S01-S03, and does not need new equipment. The energy density of the whole package can reach 60-65 Wh/kg, the whole package is completely free of lithium, cobalt and nickel, the safety is greatly improved, and the whole package is perfectly suitable for scenes such as ultrahigh-voltage industry, rail transit, flexible direct current of a power grid and the like.

Inventors

  • Request for anonymity

Assignees

  • 广西钦州市华源电子有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The oxide composite electrolyte high-voltage energy storage device is characterized by comprising a multi-layer serial cell body, two-side heteropolar composite electrodes, an oxide-polymer composite electrolyte and an edge full-encapsulation insulating layer; the double-side heteropolar composite electrode comprises a metal-based composite copper-aluminum foil current collector, a carbon nano anchoring layer and an active layer, wherein a copper layer on one side of the current collector is coated with a hard carbon negative electrode, and an aluminum layer on the other side of the current collector is coated with a graphite positive electrode, so that a single-foil double-unit serial structure is formed; the multi-layer series connection cell body is formed by alternately laminating the double-side heteropolar composite electrodes and the diaphragms, and the number of layers is 50-100; the oxide-polymer composite electrolyte is filled in the pores of the electrode and the diaphragm; the edge full-encapsulation insulating layer is coated on the periphery of the multi-layer serial battery core body.
  2. 2. The energy storage device according to claim 1, wherein the carbon nano anchoring layer is coated on the surfaces of both sides of the current collector in a full width mode, the thickness is 50-100 nm, and a continuous conductive network is formed between the carbon nano anchoring layer and the current collector and the active layer.
  3. 3. The energy storage device of claim 1, wherein the oxide-polymer composite electrolyte is Nb-doped LLZO powder modified PVDF composite electrolyte having a single cell withstand voltage of 20V or more.
  4. 4. The energy storage device according to claim 1, wherein an insulating margin area with a width of 1.5-3 mm is reserved around the double-sided hetero-electrode composite electrode, and the insulating margin area is free of an active layer and an anchoring layer.
  5. 5. The energy storage device of claim 1, wherein the rated operating voltage of the multi-layer series cell body is greater than or equal to 1000V without an external module being connected in series-parallel.
  6. 6. The energy storage device of claim 1, wherein the edge fully encapsulated insulating layer is a boron nitride modified flexible insulating layer that provides both insulating and thermally conductive functions.
  7. 7. The energy storage device of claim 1, wherein the energy storage device is free of any elemental lithium, cobalt, nickel, and free-flowing liquid electrolyte.
  8. 8. The energy storage device of claim 1, wherein the energy storage device has a cycle life of greater than or equal to 10 ten thousand times and a capacity retention of greater than or equal to 85%.
  9. 9. A method for producing the oxide composite electrolyte high-voltage energy storage device according to any one of claims 1 to 8, comprising the steps of: s1, preparing an electrode, namely preparing a double-side heteropolar composite electrode by adopting the method of S01, wherein a copper layer on one side of a current collector is coated with a hard carbon negative electrode, and an aluminum layer on the other side of the current collector is coated with a graphite positive electrode; S2, nondestructive lamination, namely alternately laminating the composite electrode and the diaphragm by adopting a nondestructive transfer positioning lamination method of S02 to form a multilayer series-connection cell body; S3, curing the composite electrolyte, namely injecting an oxide-polymer composite electrolyte precursor by adopting a vacuum infiltration and gradient hot-pressing process, and curing to form a solid electrolyte; And S4, insulating packaging, namely packaging the multi-layer series-connection battery core body by adopting an edge full-encapsulation insulating process of S03, so as to obtain a finished energy storage device.
  10. 10. The preparation method according to claim 9, wherein the vacuum degree of vacuum infiltration in the step S3 is-0.08 to-0.1 MPa, the gradient hot-pressing temperature is 80-150 ℃, and the pressure is 0.5-2 MPa.

Description

Oxide composite electrolyte high-voltage energy storage device and preparation method thereof Technical Field The invention belongs to the technical field of electrochemical energy storage devices and manufacturing, and particularly relates to a 1000V or more internal multilayer series connection straight-out oxide composite electrolyte high-voltage energy storage device and a preparation method thereof. Background The oxide solid electrolyte has high ionic conductivity, wide voltage window, excellent thermal stability and chemical stability, and is considered as an ultimate solution to solve the safety problem of the conventional liquid energy storage device. The prior oxide solid state energy storage technology has the following fatal defects: 1. The brittleness of the pure ceramic cannot be overcome, the oxide ceramic electrolyte such as LLZO, LATP and the like has high hardness and large brittleness, is extremely easy to crack in the lamination and circulation processes, causes internal short circuit, and has the mass production yield of less than 30 percent; 2. the total low-voltage single bodies are connected in series and parallel outside, wherein the highest single body voltage is only 4.2V, more than 240 single bodies are required to be connected in series and parallel to reach the 1000V system voltage, the system cost is high, and the reliability is low; 3. the prior art considers that the internal multi-layer series connection can cause electrolyte interface failure and can not realize high-voltage straight-out; 4. the process compatibility is extremely poor, special ceramic sintering, ultrathin electrolyte coating and high-temperature hot pressing equipment are required to be newly added, the transformation cost of a single production line exceeds 1 hundred million yuan, and the rapid mass production cannot be realized. Currently, no patent exists worldwide to combine Nb doped LLZO composite electrolyte with a "double-sided hetero-current collector + lossless lamination + edge fully encapsulated insulation" core structure, and therefore development of a corresponding oxide composite electrolyte high voltage energy storage device and a method for manufacturing the same is needed. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide an oxide composite electrolyte high-voltage energy storage device and a preparation method thereof, solves the problem of brittleness of pure ceramics through an oxide-polymer composite electrolyte, directly realizes high-voltage straight-out of more than 1000V through an internal multilayer serial structure, and perfectly multiplexes the existing whole set of core manufacturing process. In order to achieve the above purpose, the invention adopts the following technical scheme: first aspect energy storage device technical solution An oxide composite electrolyte high-voltage energy storage device comprises a multi-layer serial cell body, double-side heteropolar composite electrodes, an oxide-polymer composite electrolyte and an edge full-encapsulation insulating layer. The double-side heteropolar composite electrode comprises a metal-based composite copper-aluminum foil current collector, a carbon nano anchoring layer and an active layer, wherein a copper layer on one side of the current collector is coated with a hard carbon negative electrode, an aluminum layer on the other side of the current collector is coated with a graphite positive electrode, a single-foil double-unit series structure is formed, the multi-layer series cell body is formed by alternately laminating double-side heteropolar composite electrodes and diaphragms, the number of layers is 50-100, oxide-polymer composite electrolyte is filled in pores of the electrodes and the diaphragms, and the periphery of the multi-layer series cell body is fully encapsulated with an insulating layer. Further, the carbon nano anchoring layer enables the binding force between the active layer and the current collector to be more than or equal to 8N/cm, the interfacial resistance to be reduced by more than 50%, the particle size of the Nb-doped LLZO powder is 100-500 nm, the doping amount is 5-10%, and the ionic conductivity of the composite electrolyte is improvedThe thermal decomposition temperature is more than or equal to 350 ℃. Further, an insulating margin area of 1.5-3 mm is reserved around the electrode, and the electrode is perfectly matched with an S02 lossless lamination and S03 edge full encapsulation process, and is 100% compatible with the existing production line. Second aspect, preparation method The preparation method of the oxide composite electrolyte high-voltage energy storage device comprises the following steps: s1, preparing an electrode, namely preparing a double-side heteropolar composite electrode by adopting the method of S01, wherein a copper layer on one side of a current collector is coated with a petroleum coke-based hard carbon negative electrode,