阅读说明：本技术 一种耐压高体积比能量电池组及其焊接方法 (Pressure-resistant high-volume-ratio energy battery pack and welding method thereof ) 是由 王磊 裴波 张明 田龙飞 李围 于 2021-01-13 设计创作，主要内容包括：本发明公开了一种耐压高体积比能量电池组,包括盖板和钛合金壳体焊接形成的腔体以及设置在腔体内的电池单体、电路板和线缆等电子元器件,所述的盖板外分别设置有电连接器、通讯连接器和泄压阀,盖板和壳体内壁面的非焊接区域均涂覆一层厚度为100～200μm的SiO-2绝热气凝胶,所述的壳体与电池单体、电路板和线缆等电子元器件之间采用厚度为1～2mm的玻璃纤维布隔绝；采用干冰辅助氩弧焊焊接技术,在盖板上分别开设气密口一和气密口二,将干冰密封装置与气密口一和气密口二连通,使用氩弧焊焊接技术对盖板与壳体进行焊接。本发明专利电池组能充分利用腔体内部空间,具有较高体积比能量。(The invention discloses a pressure-resistant high-volume-ratio energy battery pack which comprises a cavity formed by welding a cover plate and a titanium alloy shell, and electronic components such as a battery monomer, a circuit board, a cable and the like arranged in the cavity, wherein an electric connector, a communication connector and a pressure release valve are respectively arranged outside the cover plate, and non-welding areas of the inner wall surfaces of the cover plate and the shell are coated with a layer of material with the thickness of100 to 200 μm of SiO 2 The heat insulation aerogel is isolated from electronic components such as a battery monomer, a circuit board and a cable by adopting glass fiber cloth with the thickness of 1-2 mm; and a first air-tight opening and a second air-tight opening are respectively formed on the cover plate by adopting a dry ice auxiliary argon arc welding technology, the dry ice sealing device is communicated with the first air-tight opening and the second air-tight opening, and the cover plate and the shell are welded by using the argon arc welding technology. The battery pack disclosed by the invention can fully utilize the internal space of the cavity and has higher volumetric specific energy.)

1. The pressure-resistant high-volume-ratio energy battery pack is characterized by comprising a cavity formed by welding a cover plate (1) and a titanium alloy shell (2), and a battery monomer, a circuit board and a cable which are arranged in the cavity, wherein the cover plate (1) is externally provided with an electric connector (3), a communication connector (4) and a pressure release valve (5) respectively, and non-welding areas of the inner wall surfaces of the cover plate (1) and the shell (2) are coated with a layer of SiO with the thickness of 100-200 mu m₂Adiabatic aerogel, casing (2) and battery monomer, circuit board and cable between adopt thickness to be 1 ~ 2 mm's glass fiber cloth isolated.

2. The battery pack of claim 1, wherein the cells are lithium batteries with a volumetric specific energy of 620-650 Wh/L or lithium ion batteries with a volumetric specific energy of 460-480 Wh/L.

3. A method of welding a high pressure capacity high volumetric specific energy battery as defined in claim 1, comprising the steps of:

step 1, respectively arranging a first airtight opening (6) and a second airtight opening (7) on a cover plate (1), communicating a dry ice sealing device with the first airtight opening (6) and the second airtight opening (7), and enabling gaseous carbon dioxide to enter a cavity from the first airtight opening (6) and flow out from the second airtight opening (7) at a flow rate of 300-500 mL/min to ensure that a battery monomer, a circuit board and a cable are immersed in a carbon dioxide protection environment;

and 2, welding the cover plate (1) and the shell (2) by using argon arc welding with the power of 600-900W, wherein the welding speed is 10-20 mm/min and is uniform.

Technical Field

The invention belongs to the technical field of battery packs, and relates to a pressure-resistant high-volume-ratio energy battery pack and a welding method of a cover plate and a shell of the battery pack.

Background

Lithium batteries or lithium ion battery packs have been used in underwater equipment due to their good electrochemical properties. But whether the battery can bear underwater pressure is still a bottleneck limiting the application. In the field, it is common to use a housing to withstand the pressure. The cover plate and the shell are generally in a mechanical sealing mode, corresponding sealing interfaces are required to be reserved between the cover plate and the shell in the mechanical sealing mode, the volume utilization rate of some small-sized battery packs is reduced, and the volumetric specific energy of the battery packs is reduced. How to effectively improve the pressure capability and the volume utilization rate of the battery pack becomes a difficult problem of the underwater power supply technology.

The volume utilization rate can be improved by adopting a welding and integrated forming technology between the cover plate and the shell. However, the welding temperature is high, and the cover plate and the shell are good heat conductors, so that electronic components such as a battery monomer, a circuit board and a cable are easily damaged, and the safety of the battery pack in the welding process is affected.

How to consider the high volumetric specific energy and the safety of the battery pack is one of the problems to be solved urgently in the technical development of the existing underwater lithium battery pack.

Disclosure of Invention

In view of the above-mentioned deficiencies of the prior art, it is an object of the present invention to provide a high volumetric specific energy battery pack that is resistant to voltage.

The technical scheme adopted by the invention for solving the technical problems is as follows: a pressure-resistant high-volume-ratio energy battery pack comprises a cavity formed by welding a cover plate and a titanium alloy shell, and electronic components such as a battery monomer, a circuit board, a cable and the like arranged in the cavity, wherein an electric connector, a communication connector and a pressure release valve are respectively arranged outside the cover plate, and a layer of SiO with the thickness of 100-200 mu m is coated on non-welding areas of the inner wall surfaces of the cover plate and the shell₂Adiabatic aerogel, electronic components such as casing and battery monomer, circuit board and cable between adopt thickness to be 1 ~ 2 mm's glass fiber cloth isolated.

The single battery of the pressure-resistant high-volumetric-specific-energy battery pack is a lithium battery with volumetric-specific energy of 620-650 Wh/L or a lithium ion battery with volumetric-specific energy of 460-480 Wh/L.

The invention also aims to provide a welding method of the high-pressure-resistant high-volume-ratio energy battery pack, which adopts a dry ice assisted argon arc welding technology and comprises the following steps:

step 1, respectively forming an air-tight opening I and an air-tight opening II on a cover plate, communicating a dry ice sealing device with the air-tight opening I and the air-tight opening II, and enabling gaseous carbon dioxide to enter a cavity from the air-tight opening I and flow out from the air-tight opening II at a flow rate of 300-500 mL/min, so as to ensure that electronic components such as a battery monomer, a circuit board, a cable and the like are immersed in a carbon dioxide protective environment before welding and in the whole welding process;

and 2, welding the cover plate and the shell by using an argon arc welding technology with the power of 600-900W, wherein the welding speed is 10-20 mm/min, and the gas blow-by flow detection device of the proton exchange membrane fuel cell stack is uniform.

The invention has the following beneficial effects:

according to the invention, the welding areas of the cover plate and the inner wall of the shell except the welding area are all coated with aerogel, the temperature of the cover plate and the shell in the welding process is controlled within the bearable range of electronic components by using a dry ice assisted argon arc welding technology, and the electronic components such as a battery monomer, a circuit board and a cable are prevented from being directly contacted with the titanium alloy shell by using glass fiber cloth, so that the battery pack disclosed by the invention can fully utilize the inner space of the cavity and has higher volumetric specific energy.

Drawings

Fig. 1 is a front view of a battery pack of the present invention;

fig. 2 is a plan view of the battery pack of the present invention.

The figures are numbered: 1-cover plate, 2-shell, 3-electric connector, 4-communication connector, 5-pressure relief valve, 6-first airtight opening, 7-second airtight opening.

Detailed Description

The invention is described in further detail with reference to the following figures and examples:

example 1

Referring to fig. 1, the pressure-resistant high-volumetric-specific-energy battery pack disclosed by the invention comprises a cavity formed by welding a cover plate 1 and a titanium alloy shell 2, and electronic components such as a battery monomer, a circuit board, a cable and the like arranged in the cavity, wherein an electric connector 3, a communication connector 4 and a pressure release valve 5 are respectively arranged outside the cover plate 1, and a layer of SiO with the thickness of 100-200 μm is coated on non-welding areas of the inner wall surfaces of the cover plate 1 and the shell 2₂Adiabatic aerogel, casing 2 and battery monomer, circuit board and cable isoelectron components between adopt thickness to be 1 ~ 2 mm/glass fiber cloth isolated.

Wherein the battery monomer includes lithium cell, lithium ion battery: the volume ratio energy of the lithium battery is 620-650 Wh/L; the volume specific energy of the lithium ion battery is 460 Wh/L-480 Wh/L.

The lithium battery or the lithium ion battery has wide application space underwater. A pressure-resistant high-volumetric-specific-energy battery has high volumetric-specific energy and high safety, and can meet the requirements of underwater servicing development. The preparation method has the advantages of simple process, simple operation and good operability.

Example 2

Referring to fig. 2, the welding method of the pressure-resistant high volumetric specific energy battery pack disclosed by the invention adopts a dry ice assisted argon arc welding technology, and comprises the following steps:

step 1, respectively forming an air-tight opening I6 and an air-tight opening II 7 on a cover plate 1, communicating a dry ice sealing device with the air-tight opening I6 and the air-tight opening II 7, and enabling gaseous carbon dioxide to enter a cavity from the air-tight opening I6 and flow out from the air-tight opening II 7 at the flow rate of 300-500 mL/min, so as to ensure that electronic components such as a battery monomer, a circuit board, a cable and the like are immersed in the protective environment of the carbon dioxide before welding and in the whole welding process;

and 2, welding the cover plate 1 and the shell 2 by using an argon arc welding technology with the power of 600-900W, wherein the welding speed is 10-20 mm/min and is uniform.

Example 3

Coating a layer of SiO on the welding-removed areas of the cover plate 1 and the shell 2₂The thickness of the heat insulation aerogel is 150 micrometers, then a layer of 1 mm glass fiber cloth is placed on the cover plate 1 and the shell 2, the single battery is a lithium-carbon fluoride battery, the single battery, a circuit board, a cable and other electronic components are connected and placed in the cavity, the thickness of the shell 2 of the battery is 4mm, and a first 6 air-tight openings are formed in the position through a dry ice sealing device₂And controlling the flow rate to be 400mL/min, and enabling the gas to flow out of the second airtight opening 7 and enter the dry ice sealing device. Before starting welding and in the whole welding process, the inner part of the battery pack is immersed in the protective environment of argon, the cover plate 1 and the shell 2 are welded by using an argon arc welding technology, the argon arc welding power is 800W, and the welding speed is uniform and is 15 mm/min. The volumetric specific energy of the battery was 630 Wh/L.

Example 4

Coating a layer of SiO2 heat-insulating aerogel with the thickness of 200 mu m on welding areas of the cover plate 1 and the shell 2, then placing a layer of 2mm glass fiber cloth on the cover plate 1 and the shell 2, selecting lithium-iron phosphate batteries as battery monomers, connecting the battery monomers, a circuit board, cables and other electronic components, placing the battery monomers into a cavity, wherein the thickness of the battery shell 2 is 5mm, and forming a CO 6 part of an airtight opening through a dry ice sealing device₂And controlling the flow rate to be 500mL/min, and enabling the gas to flow out of the second airtight opening 7 and enter the dry ice sealing device. Ensuring that the interior of the battery pack is immersed in the protective environment of argon gas before the welding and in the whole welding process, and welding the cover plate 1 and the shell 2 by using an argon arc welding technology, wherein the argon arc welding power is 780W, and the welding speed is highThe degree is uniform and is 20 mm/min. The volumetric specific energy of the battery is 470 Wh/L.

The foregoing embodiments are merely exemplary and illustrative of the present invention, and various modifications, additions and substitutions may be made by those skilled in the art to the specific embodiments described without departing from the spirit of the invention or exceeding the scope of the claims set forth herein.