Metal lithium battery negative electrode, preparation method thereof and lithium secondary battery

A battery negative electrode and metal lithium technology, which is applied in the field of metal lithium battery negative electrode and lithium secondary battery, can solve the problems of capacity retention, cycle life, low energy density, etc., and achieve the promotion of lithium ion crossing and good compatibility , The effect of improving cycle performance

Active Publication Date: 2021-04-09
NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] However, the coated lithium foil prepared by the above method is only suitable for low capacity density (2 )’s positive electrode is assembled into a battery, that is, it is only suitable for a battery system with a low en

Method used

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  • Metal lithium battery negative electrode, preparation method thereof and lithium secondary battery
  • Metal lithium battery negative electrode, preparation method thereof and lithium secondary battery
  • Metal lithium battery negative electrode, preparation method thereof and lithium secondary battery

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preparation example Construction

[0021] The invention provides a method for preparing a metal lithium battery negative electrode, comprising the following steps:

[0022] a) under anhydrous conditions, the silane coupling agent and cyanoacrylate are transesterified in an anhydrous solvent to obtain a solution containing transesterified products;

[0023] b) coating the solution containing the transesterification product on the surface of the negative electrode foil and drying to obtain a negative electrode containing a protective layer.

[0024] In the present invention, a specific silane coupling agent is transesterified with cyanoacrylate to form a transesterified product, which is coated on the surface of the negative electrode foil. After coating, anionic polymerization is initiated by Li or a small amount of water in the air. Make the transesterification product form a spatially cross-linked polymer. The cross-network polymer coating can effectively promote the penetration of lithium ions, induce lithium...

Embodiment 1

[0051] S1. Under the protection of nitrogen, dimethyldimethoxysilane and methyl cyanoacrylate were successively dissolved in NMP, heated to 120° C., stirred and refluxed for 8 hours, and transesterified to obtain a solution containing transesterified products.

[0052] S2. After cooling to room temperature, the above solution containing the transesterification product is coated on the surface of the metal lithium foil, the thickness of the foil is 50 μm, and the coating thickness of the solution is 60 μm.

[0053] S3. Dry the coated foil at 80° C. for 10 h, and then carry out processes such as rolling and cutting to prepare a negative electrode sheet. The pole piece is a disc with a diameter of 15 mm, and the obtained negative electrode is denoted as C1.

Embodiment 2

[0055] The negative electrode was prepared according to the preparation process of Example 1, except that dimethyldimethoxysilane was replaced by dimethyldiethoxysilane, and the obtained negative electrode was denoted as C2.

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Abstract

The invention provides a metal lithium battery negative electrode, a preparation method thereof and a lithium secondary battery. The negative electrode provided by the invention can improve the cycle performance of the battery under the condition of high capacity density. A specific silane coupling agent and cyanoacrylate are subjected to transesterification to form a transesterification product, the surface of a negative electrode foil is coated with the transesterification product, and after coating, an anionic polymerization reaction is initiated by Li or a small amount of water in air, so that the transesterification product forms a spatial cross-linked network polymer; the cross-linked network polymer coating can effectively promote lithium ion penetration and induce lithium ions to deposit on the surface of the negative electrode foil, has good compatibility with the negative electrode foil, and can inhibit growth of lithium dendrites; the cross-linked network polymer coating is insoluble in electrolyte, so that side reaction between the electrolyte and metal lithium can be well inhibited; the cycle performance of the battery can be effectively improved through the effects in multiple aspects.

Description

technical field [0001] The invention relates to the technical field of lithium batteries, in particular to a metal lithium battery negative electrode, a preparation method thereof and a lithium secondary battery. Background technique [0002] Traditional LIBs (lithium-ion batteries) include several important components: positive and negative electrode materials, positive and negative electrode current collectors, electrolytes, and separators. While graphite has proven to be by far the best and most reliable substance for making cathodes, it can hold a limited number of ions. Researchers have been hoping to replace graphite with lithium metal, which can hold more ions and has a very high theoretical capacity (3860mAh g -1 ) and the lowest negative potential (-3.04V compared to the standard hydrogen electrode); but usually the lithium metal is too active, especially prone to adverse reactions with the electrolyte, forming an SEI film on the Li surface, which is almost infinit...

Claims

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Application Information

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IPC IPC(8): H01M4/62H01M4/139H01M10/0525
CPCH01M4/628H01M4/139H01M10/0525H01M2004/027Y02E60/10
Inventor 骆浩刘兆平
Owner NINGBO INST OF MATERIALS TECH & ENG CHINESE ACADEMY OF SCI
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