CN203746991U - Lithium battery pack for electric vehicle - Google Patents

Abstract

The utility model discloses a lithium battery pack for an electric vehicle, comprising a small-capacity power-type module and a large-capacity capacity-type lithium battery pack, wherein the positive electrode of the power-type module is connected with the positive electrode of the capacity-type lithium battery pack, and the negative electrode of the power-type module is connected with the negative electrode of the capacity-type lithium battery pack; the nominal voltage of the power-type module is not lower than the nominal voltage of a capacity-type lithium battery module, and the highest charging voltage that the power-type module can bear is higher than the highest charging voltage that the capacity-type module can bear; the power-type module is connected with a voltage balance circuit, and the capacity-type lithium battery pack is connected with a current limiting circuit in series. The utility model provides the lithium battery pack for the electric vehicle, which takes both current discharging capacity and specific energy into consideration and effectively meets the requirement of travel distance.

Description

Lithium battery pack for electric vehicle

technical field

The utility model relates to a power supply for vehicles, in particular to a lithium battery pack for electric vehicles. the

Background technique

In 2012, global sales of electric vehicles (including PHEVs and EVs) reached 129,600 units, almost doubling from 68,000 units in 2011, the first year of commercialization of electric vehicles. Although it is still not worth mentioning compared with traditional cars with tens of millions of sales volume, for a new thing of electric vehicles, it is still very good to achieve such results in the first two years. In the next few years, the global electric vehicle market will roughly double every year and grow upwards. By 2015, the global annual sales of electric vehicles will exceed 1 million. the

The existing lithium battery packs for electric vehicles can usually choose a power type lithium battery module or a capacity type lithium battery module. For a power type lithium battery module, it has a large current discharge capacity, but the specific energy is small, and it is difficult to meet the mileage of an electric vehicle. Requirements for capacity; for capacity lithium battery modules, they have high specific energy, but it is difficult to withstand large current discharge, and the battery is prone to heat, which affects the life of the battery and is prone to safety hazards. the

If a power type lithium battery module for electric vehicles, especially a supercapacitor, is selected, its specific energy is low and its cost is high, which cannot meet the mileage requirements of electric vehicles. the

If the capacity type lithium battery module for electric vehicles is selected, due to the relatively poor discharge capacity of large currents, the temperature of the battery pack is prone to rise and is uneven, causing problems such as short battery life and potential safety hazards; the

If a medium-power lithium battery module for electric vehicles is selected, although the power and capacity characteristics are taken into account, it is currently difficult to meet the requirements of the mileage, power and cost of electric vehicles. the

Contents of the invention

In order to overcome the shortcomings of the existing lithium battery packs for electric vehicles that cannot take into account the current discharge capacity, specific energy and mileage requirements, the utility model provides a battery pack for electric vehicles that takes into account the current discharge capacity and specific energy and effectively meets the mileage requirements. Lithium battery pack. the

The technical scheme that the utility model solves its technical problem adopts is:

A lithium battery pack for electric vehicles, comprising a small-capacity power module and a large-capacity capacity lithium battery pack, the positive pole of the power module is connected to the positive pole of the capacity lithium battery pack, and the power module The negative pole of the capacity type lithium battery pack is connected to the negative pole of the capacity type lithium battery pack; the nominal voltage of the power type module is not lower than the nominal voltage of the capacity type lithium battery module, and the maximum charging voltage of the power type module is higher than The highest charging voltage that the capacity type module can withstand; the power type module is connected in parallel with the equalizing circuit, and the capacity type lithium battery pack is connected in series with the current limiting circuit.

Further, the power module is a supercapacitor module or a power lithium battery module. the

Still further, the positive pole or negative pole is connected in series with a circuit breaker and a relay in sequence. the

Furthermore, the capacity type lithium battery module is connected with a protection circuit. the

The power module is connected with a first acquisition circuit for acquiring voltage and temperature signals. the

The capacity type lithium battery pack is connected with a second acquisition circuit for acquiring voltage and temperature signals. the

The beneficial effects of the utility model are mainly manifested in: 1) The lithium battery pack formed by parallel connection of a small-capacity power module and a large-capacity capacity lithium battery module takes into account both power and capacity characteristics, and meets the operating conditions and cost of electric vehicles. Requirements; 2) The power-type module is always in an under-charged state during charging to improve charging efficiency and reduce temperature rise during charging; 3) The capacity-type lithium battery module has a signal (voltage and temperature) acquisition and voltage equalization circuit, the main The loop has a current limiting device and circuit to control the discharge current and prolong the life of the lithium battery pack; 4) The lithium battery pack is equipped with a relay and a fuse device to improve the safety of the lithium battery pack. the

Description of drawings

FIG. 1 is a schematic diagram of a lithium battery pack for an electric vehicle. the

Fig. 2 is a schematic diagram of another lithium battery pack for electric vehicles. the

Fig. 3 is a schematic diagram of another lithium battery pack for an electric vehicle. the

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described. the

Referring to Figures 1 to 3, a lithium battery pack for an electric vehicle includes a small-capacity power module 2 and a large-capacity capacity lithium battery pack 1, the positive electrode of the power module 2 is connected to the capacity lithium battery The positive pole of the group 1 is connected, and the negative pole of the power module 2 is connected to the negative pole of the capacity lithium battery pack 1; the nominal voltage of the power module 2 is not lower than the nominal voltage of the capacity lithium battery module 1 , and the highest charging voltage that the power module 2 can bear is higher than the highest charging voltage that the capacity module 1 can bear; the power module 2 is connected to a balancing circuit, and the capacity lithium battery pack 1 is connected to a current limiting circuits in series. the

Further, the power module 2 is a supercapacitor module or a power lithium battery module, wherein Fig. 1 and Fig. 2 are supercapacitor modules, and Fig. 3 is a power lithium battery module. the

Still further, the positive pole or negative pole is connected in series with a circuit breaker and a relay in sequence. the

Furthermore, the capacity type lithium battery module 1 is connected with a protection circuit. the

The power module 2 is connected with a first acquisition circuit for acquiring voltage and temperature signals. the

The capacity lithium battery pack 1 is connected with a second acquisition circuit for acquiring voltage and temperature signals. the

In this embodiment, a small-capacity power module 2 is connected in parallel with a large-capacity lithium battery module 1 to form a lithium battery pack for electric vehicles;

Power module 2 has good high current charge and discharge capability and over-discharge resistance;

The nominal voltage of the power type module 2 is not lower than the nominal voltage of the capacity type lithium battery module 1 , and the charging voltage that the power type module 2 can withstand is higher than that of the capacity type module 1 . In the later stage of charging, the power module is not fully charged to improve the charging efficiency of the lithium battery pack and reduce the temperature during charging.

The capacity-type lithium battery module 1 has high specific energy and safety characteristics, and meets the requirement of electric vehicle mileage on discharge energy. the

The power module 2 has a first signal acquisition circuit and an equalization circuit for collecting voltage and temperature; the capacity type lithium battery module 1 has a second signal acquisition circuit and a protection circuit for collecting voltage and temperature, and a main circuit current limiting Devices and circuits to control the size of its discharge current. the

The entire lithium battery pack for electric vehicles is equipped with a circuit breaker, relay and fuse device to improve the safety of the lithium battery pack. the

Claims (6)

1. an electric vehicle lithium battery bag, it is characterized in that: the power-type module and the jumbo capacity type lithium battery group that comprise low capacity, the positive pole of described power-type module is connected with the positive pole of described capacity type lithium battery group, and the negative pole of described power-type module is connected with the negative pole of described capacity type lithium battery group;

The nominal voltage of described power-type module is not less than the nominal voltage of capacity type lithium battery module, and the described power-type module charging ceiling voltage that can the bear maximum charging voltage that can bear higher than capacity type module;

Described power-type module is connected with voltage balance circuit, and described capacity type lithium battery group is connected with current-limiting circuit.

2. electric vehicle lithium battery bag as claimed in claim 1, is characterized in that: described power-type module is super capacitor module or power lithium battery module.

3. electric vehicle lithium battery bag as claimed in claim 1 or 2, is characterized in that: described negative or positive electrode is connected in series successively with circuit breaker, relay.

4. electric vehicle lithium battery bag as claimed in claim 1 or 2, is characterized in that: described capacity type lithium battery module and protective circuit are connected.

5. electric vehicle lithium battery bag as claimed in claim 1 or 2, is characterized in that: described power-type module be connected in order to the first Acquisition Circuit that gathers voltage and temperature signal.

6. electric vehicle lithium battery bag as claimed in claim 1 or 2, is characterized in that: described capacity type lithium battery group be connected in order to the second Acquisition Circuit that gathers voltage and temperature signal.