TWI643379B - Rechargeable lithium ion battery with plastic case - Google Patents

Abstract

The invention relates to a rechargeable lithium ion battery with a plastic shell, comprising a plastic shell, a positive electrode, a negative electrode, a core element, a positive electrode guide and a negative electrode guide, the plastic shell comprising a first cover body and a first cover body a second cover body and an accommodating space, the first cover body has a first opening, the second cover body has a second opening, the positive electrode is embedded in the first cover body, and the negative electrode is embedded in the first cover body a second cover body, the core element is disposed in the accommodating space and includes a laminated body having a positive electrode contact and a negative electrode contact, the positive electrode lead is connected to the positive electrode contact and the positive electrode, The negative electrode lead is connected to the negative electrode contact and the negative electrode. By changing the thickness of the plastic case, the size of the accommodating space can be increased, thereby increasing the volumetric energy density.

Description

Rechargeable lithium ion battery with plastic case

The invention relates to a lithium ion battery, in particular to a rechargeable lithium ion battery with a plastic shell.

Lithium-ion battery is a rechargeable battery. It relies on the movement of lithium ions between the positive and negative electrodes to convert chemical energy into electrical energy. It has the advantages of high energy density, no memory effect, and a large number of Applied to 3C products, such as smart phones and tablets, and as time goes by, wearable electronic devices are the next wave of development goals, therefore, how to make lithium-ion batteries in line with wearable electronic devices The goal of big manufacturers.

The lithium ion battery that can be applied to the wearable electronic device is mainly a small-sized button battery product, such as the "button battery and its production method" of the Chinese Patent No. CN 1178325, which comprises an outer casing and a casing cover. An insulating gasket and an electrode assembly, the outer casing is connected to the outer casing cover through the insulating gasket, and the electrode assembly is disposed in the outer casing and the outer casing cover and has a positive electrode and a negative electrode.

Generally, the outer casing is a positive electrode and the outer casing cover is a negative electrode, and is made of metal. However, if the outer casing of the battery is made of a metal material, it has the disadvantages of heavy weight and high processing cost, and the metal casing has a disadvantage. It may also cause expansion and explosion due to factors such as failure of external protection board, improper overcharge or over discharge, high temperature environment and internal short circuit, and raise safety concerns. Therefore, how to reduce the weight, reduce the cost, and improve the safety of use is a problem that the relevant industry wants to solve.

The main object of the present invention is to solve the problem of heavy weight, high cost, and low safety by using a battery of a metal casing.

To achieve the above objective, the present invention provides a rechargeable lithium ion battery having a plastic case, comprising a plastic case, a positive electrode, a negative electrode, a core element, a positive electrode lead, and a negative electrode guide. The first cover body has a first cover body, a second cover body and an accommodating space formed by sealingly engaging the first cover body and the second cover body. The first cover body has a first opening, the second cover The cover body has a second opening, the positive electrode is embedded in the first cover body and closes the first opening, the negative electrode is embedded in the second cover body and closes the second opening, and the core element is disposed in the receiving body The space includes a stacked body having a positive contact and a negative contact. The two ends of the positive lead are respectively connected to the positive contact and the positive electrode, and the two ends of the negative lead are respectively Connected to the negative electrode contact and the negative electrode.

In summary, the present invention has the following features:

1. By the arrangement of the plastic shell, the overall weight and cost can be reduced, and by changing the thickness of the plastic shell, the size of the accommodating space can be increased, thereby increasing the volumetric energy density and prolonging the battery life.

Second, the plastic shell has good mechanical and thermal stability. Even if the internal temperature or pressure of the battery is abnormally large, the plastic shell can be deformed, softened or cracked first, generating a pressure relief buffer and a heat dissipation mechanism, and reducing the risk of burning or explosion of the battery. To improve safety.

3. By embedding the positive electrode and the negative electrode in the plastic shell, the occurrence of a short circuit can be avoided, and the strength of the plastic shell can be enhanced at the same time. In addition, the positive electrode and the negative electrode do not occupy the capacity. Space is set to further increase the volumetric energy density of the battery.

10‧‧‧ plastic shell

11‧‧‧First cover

111‧‧‧First electrical connection surface

112‧‧‧ first side

12‧‧‧Second cover

121‧‧‧Second electrical connection surface

122‧‧‧Second side

13‧‧‧ accommodating space

14‧‧‧First opening

15‧‧‧second opening

20‧‧‧ positive electrode

21‧‧‧First positive electrode holder

22‧‧‧Second positive electrode holder

30‧‧‧Negative electrode

31‧‧‧First negative electrode holder

32‧‧‧Second negative electrode holder

40‧‧‧ core elements

41‧‧‧Stacked body

42‧‧‧ positive contact

43‧‧‧negative contact

44‧‧‧ positive electrode material

45‧‧‧First spacer

46‧‧‧Anode material

47‧‧‧Second insulation

50‧‧‧Actual lead

60‧‧‧Negative lead

70‧‧‧ electrolyte

Fig. 1 is an exploded perspective view showing a first embodiment of the present invention.

Figure 2 is a cross-sectional view showing the first embodiment of the present invention.

Figure 3 is an exploded perspective view of a second embodiment of the present invention.

Figure 4 is a cross-sectional view showing a second embodiment of the present invention.

Figure 5 is an exploded perspective view of a third embodiment of the present invention.

The detailed description and technical contents of the present invention will now be described with reference to the following drawings: Referring to FIG. 1 to FIG. 4, the present invention is a rechargeable lithium ion battery with a plastic case 10, which comprises There is a plastic shell 10, a positive electrode 20, a negative electrode 30, a core element 40, a positive electrode guide 50 and a negative electrode guide 60. The plastic case 10 includes a first cover 11 and a second cover 12. And an accommodating space 13 formed by sealingly joining the first cover 11 and the second cover 12, and the first cover 11 has a first opening 14, and the second cover 12 has a first a second opening 15 , the positive electrode 20 and the negative electrode 30 are respectively embedded in the first cover 11 and the second cover 12 , and respectively close the first opening 14 and the second opening 15 , the core element 40 It is disposed in the accommodating space 13 and includes a laminated body 41 having a positive electrode contact 42 and a negative electrode contact 43. The two ends of the positive electrode lead 50 are respectively connected to the positive electrode contact 42. And the positive electrode 20, the two ends of the negative electrode lead 60 are respectively connected to the negative electrode contact 43 and the negative electrode 30.

The accommodating space 13 is also filled with an electrolyte 70, which is a polycarbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), epoxy molding with different ratios. Resin (EMC), dimethyl carbonate (DMC), an organic solution of greater than or equal to one molar concentration of lithium hexafluorophosphate (1M LiPF6).

Therefore, by replacing the traditional metal casing with the plastic casing 10, the overall weight and cost can be reduced, and the manufacturing process of the plastic casing 10 is relatively simple, and the thickness of the plastic casing 10 can be changed according to different requirements. The size of the accommodating space 13 further increases the volumetric energy density and prolongs the battery life. In addition, the plastic has good mechanical and thermal stability, and the plastic shell 10 can be deformed, softened or cracked first even if the internal temperature or pressure of the battery is abnormally excessive. It generates a pressure relief buffer and a heat dissipation mechanism to reduce the risk of burning or explosion of the battery and improve safety.

In this embodiment, the first cover 11 has a first electrical connection surface 111 and a first side 112 extending from the first electrical connection surface 111 toward the second cover 12, the second cover The body 12 has a second electrical connection surface 121 and a second side 122 extending from the second electrical connection surface 121 toward the first cover 11 , and the positive electrode 20 is embedded in the first electrical connection surface 111 . The first side 112 is formed into a C-shape. Similarly, the negative electrode 30 is embedded in the second electrical connection surface 121 and the second side 122 to form a C-shape, and the first opening 14 is formed. The second opening 15 is disposed on the second electrical connection surface 121. The second opening 15 is disposed on the second electrical connection surface 121. Thus, the strength of the plastic case 10 can be enhanced, and the occurrence of a short circuit can be avoided, and the positive electrode 20 is The negative electrode 30 does not occupy the accommodating space 13, and the volume capacity density of the battery can be further increased. In this embodiment, the first cover 11 and the second cover 12 are sealed to each other by ultrasonic welding, laser welding, or glue bonding, and may be further sealed by ultrasonic welding or laser welding. Coated at the seam UV glue (UV glue) to increase its mechanical strength, and glue can be thermosetting, hot melt, room temperature curing, pressure sensitive, etc., such as industrial glue or UV glue (UV glue).

The core element 40 further includes a positive electrode material 44 stacked to form a stacked structure, a first spacer 45, a negative electrode material 46 and a second spacer 47, and the positive electrode material 44 may be a layered rock (Rock Salt). Metal oxides of spinel and olivine structures, and metal oxides of layered structure systems such as LiMO ₂ , where M is a transition metal such as trivalent cobalt, nickel, manganese or a mixture thereof Element; a metal oxide of a spinel structure such as LiMn ₂ O ₄ or LiMn ₂ -xMxO ₄ , wherein M is a transition metal element such as iron, cobalt, nickel, copper or chromium; a metal oxide of an olivine structure such as LiMPO ₄ , wherein M is a transition metal element such as divalent iron, cobalt, nickel, manganese or a mixture thereof, and the negative electrode material 46 may be graphite, lithium titanium oxide (Li ₄ Ti ₅ O ₁₂ ), titanium dioxide (TiO ₂ ) or ruthenium. Carbon (Si-C) composite material, the material of the first separator 45 and the second separator 47 may be polypropylene (PP), polyethylene (PE) or PP or PE. The film is plated with a ceramic separator of alumina (Al ₂ O ₃ ). In addition, in "FIG. 1" and "FIG. 2", the core element 40 is a winding element, and in "FIG. 3" and "FIG. 4", the core element 40 is a laminated element, and in the figure The number of layers and thickness are only illustrative, not the actual thickness and number of layers.

In the present invention, the plastic shell 10 may be made of polyformaldehyde (POM), polycarbonate (Polycarbonate, PC for short), or acrylonitrile butadiene styrene (Acrylonitrile Butadiene Styrene). ABS), Polypropylene (PP), Polymethylmethacrylate (PMMA), Styrene Acrylonitrile (SAN), Polystyrene (PS), combinations thereof, etc. The shape of the plastic shell 10 is exemplified herein by using a cylinder, but it may also be a polygonal cylinder or an irregular cylinder. The material of the positive electrode guide 50 may be aluminum, stainless steel or a combination thereof, and the material of the negative electrode guide 60 may be copper, nickel or a combination thereof.

During fabrication, the core element 40 is placed in the accommodating space 13 , and both ends of the positive electrode lead 50 are soldered to the positive electrode contact 42 and the positive electrode 20 , and both ends of the negative electrode guide 60 are Soldering the negative electrode contact 43 and the negative electrode 30, the welding may be performed by means of laser spot welding, and then filling the electrolyte 70 in the accommodating space 13 and finally using ultrasonic welding. In a manner, the first cover 11 and the second cover 12 are sealed to each other to complete the production. The battery can be charged at a conventional 4.2V or a high voltage of 4.35V to 5V.

Referring to FIG. 5, the positive electrode 20 further includes a first positive electrode holder 21 and a second positive electrode holder 22. The negative electrode 30 includes a first negative electrode holder 31 and a second negative unit. An electrode holder 32, the first positive electrode holder 21 and the second positive electrode holder 22 are embedded in the first cover 11 and intersect each other to form an angle, and the first negative electrode holder 31 and the second negative electrode The brackets 32 are also disposed in the second cover 12 and intersect each other at an angle, so that the strength of the plastic case 10 can be further enhanced. The electrode holder here is exemplified by two examples, but it can also be increased or decreased as needed.

In summary, the present invention has the following features:

1. By replacing the traditional metal casing with the plastic shell, the overall weight and cost can be reduced, and the manufacturing process of the plastic shell is relatively simple, and the thickness of the plastic shell can be changed according to different requirements, and the accommodation space can be increased. The size, which in turn increases the volumetric energy density and extends battery life.

Second, the plastic shell has good mechanical and thermal stability. Even if the internal temperature or pressure of the battery is abnormally large, the plastic shell can be deformed, softened or cracked first, generating a pressure relief buffer and a heat dissipation mechanism, and reducing the risk of burning or explosion of the battery. To improve safety.

3. By embedding the positive electrode and the negative electrode in the plastic case, the strength of the plastic case can be enhanced, the occurrence of a short circuit can be avoided, and the accommodation space is not occupied, and the volumetric energy density of the battery can be further increased.

4. The strength of the plastic shell can be further enhanced by the arrangement of the first positive electrode holder, the second positive electrode holder, the first negative electrode holder and the second negative electrode holder.

Therefore, the present invention is highly progressive and conforms to the requirements of the invention patent application, and the application is filed according to law, and the praying office grants the patent as soon as possible.

The present invention has been described in detail above, but the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the scope of the invention. That is, the equivalent changes and modifications made by the scope of the present application should remain within the scope of the patent of the present invention.

Claims (7)

The invention relates to a rechargeable lithium ion battery with a plastic shell, comprising: a plastic shell, comprising a first cover body, a second cover body and a sealing joint formed by the first cover body and the second cover body; The first cover has a first opening, and the first cover has a first electrical connection surface and a first side extending from the first electrical connection surface toward the second cover. The second cover has a second opening, the second cover has a second electrical connection surface and a second side extending from the second electrical connection surface toward the first cover; a positive electrode of the cover body, and the positive electrode closes the first opening, the positive electrode is embedded in the first electrical connection surface and the first side edge to form a C-shape, and the first opening is disposed on the first An electrical connection surface, the positive electrode includes a first positive electrode holder and a second positive electrode holder, the first positive electrode holder and the second positive electrode holder intersect each other and are at an angle; and the second cover is embedded in the second cover a negative electrode, and the negative electrode closes the second opening, the negative electrode is buried in the first The second electrical connection surface and the second side are formed into a C-shaped shape, and the second opening is disposed on the second electrical connection surface, the negative electrode includes a first negative electrode bracket and a second negative electrode bracket, the first a negative electrode holder and the second negative electrode holder intersect each other and are at an angle; a core element disposed in the accommodating space, the core element comprises a stacked body, the stacked body has a positive contact and a negative a core material comprising a positive electrode material stacked to form a stacked structure, a first separator material, a negative electrode material and a second separator material, wherein the positive electrode material is selected from the group consisting of a layered, spinel and olivine structure system a group of metal oxides, the anode material being graphite, lithium titanium oxide, titanium dioxide And a group consisting of a carbon composite material, the first separator and the second separator are made of a material selected from the group consisting of polypropylene, polyethylene, and a ceramic separator coated with alumina; a handle, the two ends of the positive lead are respectively connected to the positive contact and the positive electrode; and a negative lead, the two ends of the negative lead are respectively connected to the negative contact and the negative electrode. The rechargeable lithium ion battery with a plastic shell according to claim 1, wherein the core element is selected from the group consisting of a coiled metal and a laminated sheet. The rechargeable lithium ion battery with a plastic case according to claim 1, wherein the first cover and the second cover are sealed to each other by ultrasonic welding, glue bonding and radium. A group of welds. The rechargeable lithium ion battery with a plastic shell according to claim 1, wherein the plastic shell is made of a polyoxymethylene, a polycarbonate, an acrylonitrile-butadiene-styrene copolymer, A group consisting of polypropylene, polymethyl methacrylate, styrene propylene copolymer, polystyrene, and combinations thereof. The rechargeable lithium ion battery with a plastic case according to claim 1, wherein the shape of the plastic case is selected from the group consisting of a cylinder, a polygonal cylinder and an irregular cylinder. The rechargeable lithium ion battery with a plastic case according to claim 1, further comprising an electrolyte disposed in the accommodating space. The rechargeable lithium ion battery with a plastic case as described in claim 1, wherein the material of the positive electrode guide is selected from the group consisting of aluminum and stainless steel, and the material of the negative electrode guide is selected from the group consisting of A group consisting of copper and nickel.