CN206134886U - Lithium cell module with low temperature preheats function - Google Patents

Abstract

The utility model discloses a lithium battery module with a low-temperature preheating function, relates to a mobile power supply device, in particular to a lithium battery module with a low-temperature preheating function, and is characterized in that: the middle of the battery module is Lithium battery strings, supercapacitors are installed above the lithium battery strings, a control box is installed on the side of the lithium battery strings, a heat-conducting metal plate is installed under the lithium battery strings, a protection circuit is installed in the control box, and multiple Special Ni/4H-SiC diodes, the special Ni/4H-SiC diodes are connected with heat-conducting metal plates, the utility model solves the defect of making up for the low-temperature characteristics of lithium batteries, improves the reliability of the control part, reduces costs, and reduces battery life. The volume of the group, reducing line loss and eliminating the energy consumption of active preheating.

Description

A lithium battery module with low temperature preheating function

technical field

The utility model relates to the technical field of lithium batteries, in particular to a low-temperature preheating technology for lithium batteries.

Background technique

Lithium-ion batteries have the advantages of high energy density, long cycle life, low self-discharge rate, and no memory effect. Compared with lead-acid batteries and nickel-metal hydride batteries, they are more suitable for pure electric vehicles, plug-in electric vehicles and hybrid vehicles. It is also the main driving power of mobile phones and notebook computers and other main energy storage components. Graphite is currently the most commonly used negative electrode material for lithium-ion batteries due to its low potential, high capacity density, small irreversible capacity, and low cost. However, at low temperatures, various types of impedance inside lithium-ion batteries with graphite negative electrodes increase significantly, making it difficult to use lithium-ion batteries. In addition, due to the hidden danger of lithium analysis, the battery charge acceptance is further deteriorated. If low-temperature charging is carried out in an unreasonable way, it is easy to cause lithium metal to precipitate on the graphite negative electrode, which will not only cause the capacity attenuation and life loss of the battery, but also may continue to grow and form dendrites, which will puncture the separator, cause a short circuit, and cause thermal runaway, etc. A serious safety accident. In addition, as the temperature decreases, the discharge performance of lithium-ion batteries also deteriorates significantly, and the discharge capacity decreases to a large extent.

At present, in view of the problem of low-temperature use of batteries, one method of related technologies is to use external heating to preheat the battery on the premise of improving the thermal insulation of the power battery system, so that the battery temperature rises to room temperature or above 10°C, and then battery for use or DC charging. However, although this method can effectively solve the problem of battery charging and use at low temperatures, it still has the disadvantages of long time use, uneven heating, easy ignition and burning, large energy consumption, and high cost.

Contents of the invention

The utility model is a lithium battery module with low-temperature preheating function, adopts diode one-way non-contact conduction, cleverly uses the heat generated by the diode to preheat the battery pack, makes up for the defects of the low-temperature characteristics of the lithium battery, and improves control Partial reliability, lower costs, smaller battery packs, lower line losses and no active preheating energy consumption.

In order to achieve the above purpose, a lithium battery module with a low-temperature preheating function includes a battery module and a low-temperature preheating circuit. The middle of the battery module is a lithium battery string 1, and the top of the lithium battery string 1 is provided with Supercapacitor 2, a control box 3 is provided on the side of the lithium battery string 1, a heat-conducting metal plate 4 is provided under the lithium battery string 1, a protection circuit 5 is provided in the control box 3, and a plurality of special Ni/ 4H-SiC diode 6, the special Ni/4H-SiC diode 6 is connected with the heat-conducting metal plate 4.

The design circuit adopts the one-way non-contact conduction of the diode, and cleverly uses the heat generated by the diode to preheat the battery pack to make up for the defect of the low temperature characteristic of the lithium battery.

The practical technical solution of the utility model for the above purpose is to adopt the simplest charging and discharging circuit, select special Ni/4H-SiC diodes and heat-conducting metal plates, and the special Ni/4H-SiC diodes can withstand 500A current in the charging circuit instantaneously, and the continuous current of 200A , in the discharge circuit, it can withstand 1500A current instantaneously and continuously withstand 700A current. The switch in the circuit is completed with a special Ni/4H-SiC diode, which realizes non-contact conduction. At the same time, the heat dissipation part of the special Ni/4H-SiC diode is fixed. On the metal plate with good heat conduction, the heat generated by the special Ni/4H-SiC diode is conducted through the metal plate and diffused to the battery, realizing the preheating function for the lithium battery pack at low temperature.

Adopting the technical scheme of the utility model to manufacture the battery pack control circuit, the circuit is simplified, the cost is reduced, and the reliability of the control part is improved, the non-contact replaces the contact, the volume of the battery pack is reduced, the line loss is reduced and the active part is omitted. The energy consumption of preheating can improve the characteristic defect of lithium battery in low temperature environment.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a schematic circuit diagram of the utility model.

detailed description

As shown in Figure 1-2, a lithium battery module with a low-temperature preheating function includes a battery module and a low-temperature preheating circuit. The middle of the battery module is a lithium battery string 1, and the lithium battery string 1 A supercapacitor 2 is arranged above the lithium battery string 1, a control box 3 is arranged on the side of the lithium battery string 1, a heat-conducting metal plate 4 is arranged under the lithium battery string 1, a protection circuit 5 is arranged in the control box 3, and multiple A special Ni/4H-SiC diode 6, the special Ni/4H-SiC diode 6 is connected with the heat-conducting metal plate 4.

The negative pole of the lithium battery string 1 is connected to the protection circuit 5, and the protection circuit is connected to the positive pole of the special Ni/4H-SiC diode D1 and the negative poles of the special Ni/4H-SiC diodes D2, D3, D4, and the special Ni/4H -The negative pole of SiC diode D1 and the positive pole of special Ni/4H-SiC diodes D2, D3, D4 are connected to the negative pole of supercapacitor 2 and then connected to the negative pole of output, the positive pole of lithium battery string 1 is connected to the positive pole of supercapacitor 2 and then connected to the positive pole of output.

The design circuit adopts the one-way non-contact conduction of the diode, and cleverly uses the heat generated by the diode to preheat the battery pack to make up for the defect of the low temperature characteristic of the lithium battery.

The practical technical solution of the utility model for the above purpose is to adopt the simplest charging and discharging circuit, select special Ni/4H-SiC diodes and heat-conducting metal plates, and the special Ni/4H-SiC diodes can withstand 500A current in the charging circuit instantaneously, and the continuous current of 200A , in the discharge circuit, it can withstand 1500A current instantaneously and continuously withstand 700A current. The switch in the circuit is completed with a special Ni/4H-SiC diode, which realizes non-contact conduction. At the same time, the heat dissipation part of the special Ni/4H-SiC diode is fixed. On the metal plate with good heat conduction, the heat generated by the special Ni/4H-SiC diode is conducted through the metal plate and diffused to the battery, realizing the preheating function for the lithium battery pack at low temperature.

Adopting the technical scheme of the utility model to manufacture the battery pack control circuit, the circuit is simplified, the cost is reduced, the reliability of the control part is improved, the non-contact replaces the contact, the volume of the battery pack is reduced, the line loss is reduced and the active The energy consumption of preheating can improve the characteristic defect of lithium battery in low temperature environment.

Claims (2)

1. A lithium battery module with a low-temperature preheating function, characterized in that: it includes a battery module and a low-temperature preheating circuit, the middle of the battery module is a lithium battery string (1), and the lithium battery string ( 1) is provided with a supercapacitor (2), the side of the lithium battery string (1) is provided with a control box (3), the lower part of the lithium battery string (1) is provided with a heat-conducting metal plate (4), and the control box (3) There is a protection circuit (5) inside, and a plurality of special Ni/4H-SiC diodes (6) are arranged on the protection circuit (5), and the special Ni/4H-SiC diodes (6) and the heat-conducting metal plate (4) connect. 2. A lithium battery module with low-temperature preheating function according to claim 1, characterized in that: the negative electrode of the lithium battery string (1) is connected to a protection circuit (5), and the protection circuit is connected to a special Ni/ The anode of 4H-SiC diode D1 and the cathode of special Ni/4H-SiC diodes D2, D3, D4, the cathode of said special Ni/4H-SiC diode D1 and the cathode of special Ni/4H-SiC diodes D2, D3, D4 The positive pole is connected to the negative pole of the supercapacitor (2) and then connected to the negative pole of the output, the positive pole of the lithium battery string (1) is connected to the positive pole of the supercapacitor (2) and then connected to the positive pole of the output.