Lithium ion capacitor and negative electrode plate thereof and manufacturing method of negative electrode plate

Abstract

The invention provides a lithium ion capacitor and a negative electrode plate thereof and a manufacturing method of the negative electrode plate. The negative electrode plate of the lithium ion capacitor comprises a current collector copper foil, an active matter layer and a pre-lithiation matter layer, wherein the active matter layer is arranged on the current collector copper foil and provided with active matters having embedded and / or stripped from lithium ion performance, and the pre-lithiation matter layer is arranged on the active matter layer. The manufacturing method of the negative electrode plate of the lithium ion capacitor includes steps of coating active matter sizing on the current collector copper foil and drying and rolling the same; spraying or sputtering pre-lithiation sizing on the dried current collector copper foil coated with the active matter sizing, and drying and rolling to obtain the negative electrode plate of the lithium ion capacitor, wherein the active matter sizing contains the active matters embedded and / or stripped from lithium ion performance. The lithium ion capacitor comprises the negative electrode plate which is manufactured by the above manufacturing method. The lithium ion capacitor has the advantages that each layer of the negative electrode plate is good in lithium embedded uniformity and consistency, lithium embedding time is short, carrying a preset quantity of lithium by the negative electrode plate can be effectively controlled and the like.

Description

technical field [0001] The invention relates to an energy storage electronic device, in particular to a lithium ion capacitor, its negative pole piece and a preparation method. Background technique [0002] In recent years, with the gradual promotion of the concept of environmental protection and low carbon, clean energy technology has once again become a hot spot for technological innovation. Among them, lithium-ion capacitors are considered to be one of the effective solutions to meet people's energy needs in industry and life. [0003] Lithium-ion capacitors are asymmetric capacitors with different charging and discharging principles between the positive and negative electrodes. Combination, and at the same time, lithium ions are added to the negative electrode, which greatly improves the energy density of the capacitor. [0004] One method of pre-embedding lithium ions in the negative electrode of lithium ion capacitor is the lithium foil coating method, that is, the l...

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Problems solved by technology

[0004] One method of pre-embedding lithium ions in the negative electrode of lithium ion capacitor is the lithium foil coating method, that is, the lithium sheet arranged at the upper and lower ends of the lithium ion capacitor unit is electrochemically contacted with the negative electrode of the lithium ion capacitor, and then the electrolyte is injected into the negative electrode of the lithium ion capacitor. The negative electrode is pre-intercalated lithium, but in this lithium intercalation process, since the negative electrode plate needs to pass through the barrier of the positive electrode foil when carrying lithium ions, it takes too long to perform the lithium intercalation process, and the lithium intercalation is not uniform. As a result, the consistency of lithium-ion capacitor product performance is not high, and the yield rate is low

[0005] Another method of pre-embedding lithium ions in the negative electrode of lithium ion capacitors is a manufacturing technology for lithium ion capacitors disclosed by Japan Fuji Heavy Industries Co., Ltd. This technology introduces a third pole "lithium pole", which usually uses Elemental lithium sheet or lithium alloy, and the positive and negative current collectors are made of aluminum foil and copper foil with through-hole characteristics; then the lithium electrode is placed at the upper and lower ends of the lithium ion capacitor unit, and the electrolyte is injected. At this time, the lithium The pole begins to release lithium ions and intercalate lithium to the negative electrode. The advantage of this structure is that the positive and negative current collectors use aluminum foil and copper foil with through-hole characteristics, so the lithium intercalation is relatively uniform, but also It has brought several technical defects: Since the positive and negative current collectors use aluminum foil and copper foil with through-hole characteristics, the aluminum foil and copper foil with through-hole characteristics are not only complicated in manufacturing process, but also have high production costs, and their electrical conductivity The performance is poor, and the internal resistance (ESR) of the lithium ion capacitor produced by it is relatively large. In addition, the negative electrode pre-embedded lithium ions still takes a long time, especially the negative electrode sheet far away from the lithium extreme, and each layer of negative electrode sheet Lithium load also varies greatly

[0006] In addition, in the above-mentioned technology, because the lithium arranged in the lithium ion capacitor unit is extremely elemental lithium sheet, due to the high chemical activity of the elemental lithium, it is easy to chemically react with the moisture and oxygen in the air, so the operation of introducing the lithium electrode , need to be carried out in an anhydrous and oxygen-free external environment, which has high requirements for industrial production environment

[0007] In addition, in the above-mentioned technologies, in addition to the difference in the loading capacity of each layer of negative electrode sheets, and in the existing method, it is difficult to control whether a predetermined amount of lithium is carried by the negative electrode.

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