Sealing structure for medium-high temperature battery, medium-high temperature battery and assembly method thereof

Abstract

The invention relates to a sealing structure for a medium-high temperature battery, a medium-high temperature battery and an assembly method thereof. The sealing structure includes a metal piece for drawing current, and a closed cavity is provided inside the battery at the assembly gap where the metal piece is assembled on the battery to seal the assembly gap, and the metal piece passes through the closed cavity, and the closed cavity There are one layer, two layers, three layers or more than three layers of salt layers for liquid sealing inside, and the melting points of each salt layer decrease sequentially from the inner side of the battery to the outer side. The sealing structure of the present invention has excellent air-tightness and anti-corrosion performance, which guarantees the service life of the medium-high temperature battery when it works at 150-700°C, and also has insulation properties, which greatly reduces the mechanical strength under the condition of ensuring the mechanical strength. The volume occupied by the battery seal is reduced, saving space.

Description

technical field [0001] The invention belongs to the technical field of energy storage batteries, and in particular relates to a sealing structure for a medium-high temperature battery and an assembly method thereof. Background technique [0002] Among the existing electrochemical energy storage technologies, medium and high temperature energy storage batteries such as sodium-sulfur batteries, liquid metal batteries and other energy storage technologies have the characteristics of no pollution, high energy efficiency, flexible power and energy matching output, long life, low The maintenance cost and other advantages make it an energy storage technology with very good application prospects. [0003] The electrode materials of medium and high temperature batteries mostly use one or more of alkaline metals such as lithium, sodium, and magnesium. When the battery is working in a medium and high temperature environment (between 150°C and 700°C), the electrode material or electroly...

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Problems solved by technology

[0004] In the sealing design of high-temperature liquid metal batteries, most of them adopt the principle of assembly to achieve sealing, such as "a liquid metal battery device" (application number 201420780918.8), "semi-liquid metal electrode energy storage battery" (application number 201310131587.5) and other patents The insulating ceramic ring insulation used in the battery is installed or fastened, and the sealing performance cannot be guaranteed, and the battery structure of the above-mentioned patent is complex and bulky

[0005] For another example, patents such as "A Liquid Metal Battery Device and Its Assembly Method" (Application No. 201410350077.1) mention that "using sealed insulating ceramic parts to fasten the top of the metal current lead-out rod to the battery case" achieves sealing and insulation. The ceramic is only fastened on the metal current lead-out rod, so this sealing method cannot meet the stringent sealing requirements of liquid metal batteries at high temperatures (it may be possible to achieve sealing when fastened at room temperature, but ceramic fasteners may be damaged due to differences in material expansion coefficients at high temperatures) It is different from the thermal expansion and contraction of the fastening substrate, so that an effective seal cannot be achieved)

[0006] There are also improvements in sealing materials, such as "a sealing material for high-temperature energy storage batteries and its preparation" (application number 201310702834.2) mentions the use of CaAl 2 S 4 As a sealant, powder such as alumina + binder is used to form a sealing material for high-temperature energy storage batteries, and CaAl is required 2 S 4 As a sealant, the process is complicated by mixing powdered substances with high-temperature heat treatment to achieve sealing

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