Lithium seawater battery diaphragm, fixed sealing material and sealing method thereof

Abstract

The invention discloses a lithium seawater battery diaphragm, and a fixed sealing material. The diaphragm is a solid electrolyte diaphragm, and is a Li1+xAlxTi2-x(PO4)3 and Li1+xAlxGe2-x(PO4)3 glass-ceramic material, wherein 0. 1 <= x <= 0.6. The fixed sealing material comprises a resin, a diluent, a wetting agent and a polyethylene / polypropylene composite tab-film. The invention also discloses afixed sealing method for a lithium seawater battery diaphragm. After a low-viscosity bisphenol-A epoxy intermediate connecting layer is introduced between a solid electrolyte and the polyethylene / polypropylene composite tab-film, the diaphragm can effectively prevent debonding and water inflow caused by dissolution of a surface substance of the diaphragm in seawater while not influencing sealing performance between the diaphragm and a window material. A lithium-protected negative electrode obtained by the sealing fixing method can maintain structural stability for more than 40 days during a seawater immersion process.

Description

technical field [0001] The invention relates to the technical field of lithium battery preparation, in particular to a lithium seawater battery window, a fixed sealing material and a sealing method thereof. Background technique [0002] Lithium seawater battery is a newly developed lithium battery system with ultra-high energy density. Since the power is supplied by directly reducing water molecules in seawater, the battery does not need to carry positive active materials, and its theoretical energy density exceeds 2000Wh / kg. Ultra-high energy density lithium seawater batteries can provide high-quality power for surface and underwater equipment such as miniature AUVs and ocean buoys that require long endurance. [0003] The first thing to be solved for the practical application of lithium seawater batteries is the protection of metal lithium. Due to the violent reaction between lithium and seawater, lithium seawater batteries currently protect lithium by adding a layer of ...

AI Technical Summary

Problems solved by technology

[0004] At present, according to the type of window frame material, there are many ways to fix the glass-ceramic solid electrolyte window and the window material. The early physical mechanical method has too high requirements on the mechanical properties of the window and the operation is complicated, while the chemical bonding method does not. Difficult to achieve a good seal due to large differences in properties between window material and frame material

The patent (application number 201710195949.5) proposes a lithium seawater battery sealing method based on polyethylene\polypropylene composite ear glue, which can effectively solve the shortcomings of the above two methods and greatly increase the working time of lithium seawater batteries in seawater environments , but due to the corrosion of seawater on the solid electrolyte window, the surface of the solid electrolyte will dissolve. Therefore, the lithium seawater battery using this sealing method will be exposed to the polyethylene\polypropylene composite strip and the window when immersed in seawater for a longer period of time. Debonding occurs at the junction of the sheet, causing water to enter the negative electrode of the battery, and the battery fails.

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