GB2612437A

GB2612437A - Aging test device for multiple batteries in extruded state and test method

Info

Publication number: GB2612437A
Application number: GB2213587.5A
Authority: GB
Inventors: Wang Zhirong; Bai Jinlong; cai Qiong
Original assignee: Nanjing Tech University; University of Surrey
Current assignee: Nanjing Tech University; University of Surrey
Priority date: 2021-10-14
Filing date: 2022-09-15
Publication date: 2023-05-03
Anticipated expiration: 2042-09-15
Also published as: GB2612437A8; GB2612437B; GB202213587D0; CN113805090B; CN113805090A

Abstract

A test device for multiple batteries 3 includes a base support 19, N clamping plates 2, two motors (9, figure 5), a positioning plate 1, and a laser range finder 5. The base support has a bottom plate 6 on which polished rods 7 are vertically disposed, and the clamping plates sleeve onto the polished rods via limiting holes (8, figure 6). The clamping plates are stacked, and batteries are placed between two adjacent plates; the positioning plate is located on the Nth clamping plate. Output shafts of the motors are connected with lead screws to the positioning plate after passing through holes in the clamping plates. The laser range finder is disposed on the bottom plate on which (N-1) reflection lenses 14 are equidistantly disposed. The distances between the clamping plates, and hence battery thickness, can thus be measured. The test device can apply the same mechanical load onto batches of lithium-ion batteries to perform cyclic aging tests under the mechanical load.

Description

Aging Test Device for Multiple Batteries in Extruded State and Test Method

Technical Field

The present invention belongs to the technical field of lithium ion batteries, in particular to an aging test device for multiple batteries in an extruded state and a test method.

Background Art

Lithium ion batteries have been widely applied to new energy vehicles and energy storage stations at present due to their excellent energy storage density and working performance, but the lithium ion batteries work based on the principle of an electrochemical reaction, and thus, the variation of the long-term performance, safety and physical and chemical properties of the lithium ion batteries in different service environments is an emphasis for industry research all the time.

Cyclic aging tests on the lithium ion batteries at different temperatures and different charging/discharging rates may be completed by using a battery charging/discharging instrument and a thermostat. A battery pack of a new energy vehicle is generally used as a chassis at the same time, and it is possible that the battery pack is subjected to various mechanical shocks when the vehicle runs, which makes batteries squeezed; in addition to deformation caused by external mechanical damage, volumetric deformation of the lithium ion batteries may also be caused in a normal charging/discharging process, and the batteries in the battery pack may bear a greater planar extrusion force during work due to obvious thickness variation. Therefore, the batteries are inevitably acted by various forces in an actual use process, and these forces may act on the batteries in various forms. The lithium ion batteries work based on a reversible electrochemical reaction, and therefore, requirements on the stability of an environment are higher; and due to the actions of the forces, there may be variable and non-uniform electrochemical reaction environments inside the batteries, and therefore, influences of mechanical states of the batteries in actual use to the performances, safety and stability of the batteries need to be researched.

A special test instrument is needed to apply mechanical loads in various forms to the batteries, and other parameters of the environment where the batteries are located are controlled as much as possible, so that variables are controlled to obtain ideal test results.

Such a test performed in the past is performed on a mechanical test machine, and a battery tester is matched for data collection, but there are several innate problems in such a manner. The mechanical test machine is designed for testing the performance of a material, and therefore, its test principle is not suitable for the simultaneous test on multiple batteries. Deformation acquisition performed by the mechanical test machine is single deformation acquisition, and if there are multiple batteries, it is impossible to acquire the deformation of each battery alone, which enables the mechanical test machine to be incapable of providing enough precise data in a test process.

Summary of the Invention

The objectives of the present invention are to provide an aging test device for multiple batteries in an extruded state and a test method to solve the technical problems in the prior art that mechanical loads for testing performances of the batteries are only capable of acquiring single deformation and are incapable of acquiring the deformation of each battery alone when there are multiple batteries, which causes incapability of providing enough precise data in a test process. For solving the above-mentioned technical problems, the present invention is achieved by adopting the following technical solutions: provided is an aging test device for multiple batteries in an extruded state, including a base support. N clamping plates, two motors, a positioning plate, a pressure sensor, and a laser range finder; the base support is fixedly provided with a bottom plate on which M polished rods are vertically disposed, M limiting holes and two positioning holes are formed in each of the clamping plates, and both of the limiting holes and the positioning holes arc unthreaded holes; all the clamping plates sleeve the polished rods via the limiting holes and are located above the bottom plate, and each of the limiting holes corresponds to one of the polished rods; the N clamping plates are stacked and are sequentially marked as a first layer of clamping plate, a second layer of clamping plate,. an Nth layer of clamping plate from bottom to top, and batteries are placed between two adjacent layers of clamping plates; the positioning plate is located on the Mb layer of clamping plate, two threaded holes are formed in the positioning plate, and positions of the threaded holes correspond to positions of the positioning holes; both of M and N are positive integers greater than or equal to 3; the motors are fixedly disposed on the bottom plate, output shafts of the motors are vertical and upward, the output shaft of each of the motors is fixedly connected to a lead screw vertically disposed, and the upper end of the lead screw extends into one of the corresponding threaded holes and is in threaded connection to the positioning plate after the lead screw penetrates through a group of positioning holes corresponding to all the clamping plates; (N-1) through holes of which the coordinates are sequentially marked as { , 1), (1, 2),..., (1, N-1)) are equidistantly formed in the first layer of clamping plate; (N-2) through holes of which the coordinates are sequentially marked as 1(2, 2), (2, 3),..., (2, NA)} are equidistantly formed in the second layer of clamping plate; a through hole of which the coordinates are {(N-1, N-1)} iis formed in an (NW' layer of clamping plate; N-1 through holes of which the coordinates are (1, N-1), (2, N-1),..., (N-1, N-1) are concentrically disposed and are marked as an (N-1)th group of through holes; N-2 through holes of which the coordinates are (1, N-2), (2, N-2),..., (N-2, N-2) are concentrically disposed and are marked as an (N-2)th group of through holes; two through holes of which the coordinates arc (1, 2) and (2, 2) arc concentrically disposed and are marked as a second group of through holes; a through hole of which the coordinates are (1, 1) is marked as a first through hole; the batteries are incapable of shielding the through holes; the pressure sensor and the laser range finder are disposed on the bottom plate, (N-1) reflection lenses are equidistantly disposed on the bottom plate, and the pressure sensor and the reflection lenses are located between the bottom plate and the first layer of clamping plate; the (N-1) reflection lenses are sequentially marked as a first reflector, a second reflector an (N-1)th reflector; the lower ends of the reflection lenses are hinged with the bottom plate, the back of each of the reflection lenses is fixedly provided with a magnet, and the bottom plate is provided with (N-I) electromagnets; each of the electromagnets corresponds to one of the magnets; a limiting support enabling a working surface of each of the reflection lenses and the bottom plate to form a 45-DEG included angle is disposed on each of the reflection lenses; the height of the pressure sensor is greater than the heights of the reflection lenses which are inclined for 45 DEG; and a probe of the pressure sensor is in contact with the bottom of the first layer of clamping plate; the first reflector corresponds to the first through hole, the second reflector corresponds to the second group of through holes,..., the (N-1)th reflector corresponds to the (N-1)th group of through holes; and when an included angle formed by the (N-1)th reflector and the bottom plate is 45 DEG, other (N-2) reflection lenses cling to the bottom plate, at the moment, a reflected ray obtained after laser emitted by the laser range finder is reflected by the (N-1)° reflector penetrates through an (N-k)th group of through holes, wherein k is a positive integer smaller than or equal to N-I.

By disposing the above-mentioned test device in the present invention, N-1 lithium ion batteries to be tested are placed into the device, a lithium ion battery is placed between the two adjacent clamping plates, mechanical loads may be uniformly applied to these batteries, the mechanical loads are adjusted by using the lead screws and the motors, and the types of the mechanical loads applied to the batteries are adjusted by adjusting the shape of each layer of the multi-layer structure.

The laser range finder is matched with the reflection lenses and an electromagnetic device to intermittently measure gaps among the multi-layer structure and then indirectly measure the distance between every two layers of clamping plates, thereby achieving the purpose of measuring the deformation of each battery.

A battery tester is used to load electric loads to the batteries under the mechanical loads in batches, thereby performing charging and discharging cycle or electric abuse on the batteries and then achieving multi-abuse aging tests on the batteries.

Further preferably, positioning slots are formed in the clamping plates, the batteries are placed into the positioning slots so as to be prevented from displacing after the mechanical loads are applied. Moreover, it is ensured that the positions of new batteries placed again are consistent to the original positions, it is also ensured that the mechanical loads on all the batteries are consistent, and thus, the accuracy of test results is improved.

Further preferably, grooves in which temperature sensors are disposed are formed in bottom plates of the positioning slots, and the temperature sensors are in contact with the surfaces of the batteries. By disposing the temperature sensors, the temperatures of the batteries are monitored while the mechanical loads are loaded to the batteries.

Further preferably, the limiting supports are frames shaped like a Chinese character "Men" and are fixed to the bottom plate, and the reflection lenses are abutted with limiting cross bars of the limiting supports when upwards rotating to form a 45-DEG included angle with the bottom plate.

Further preferably, the motors are servo motors.

Provided is a test method based on the above-mentioned aging test device for multiple batteries in the extruded state, including the following steps: step 1, placing N-1 batteries to be tested into the device of claims 1 to 4, placing a battery between two adjacent clamping plates, and sequentially marking the batteries as a first battery, a second battery,..., an (N-l)th battery from bottom to top; step 2, starting two motors with the same rotating speed and rotation direction at the same time, driving, by the motors, lead screws to rotate, and then, driving a positioning plate to move downwards to extrude N layers of clamping plates and the (N-1) batteries; acquiring, by a pressure sensor, a pressure signal to a control system in real time, and after a pressure value acquired by the pressure sensor is equal to a set value, maintaining such an extruded state; step 3, measuring the thickness of the (N-1) batteries under such mechanical loads; step 4, using a battery tester to load electric loads to the (N-1) batteries under such mechanical loads in batches, and performing charging and discharging cycle or electric abuse on the batteries to achieve multi-abuse aging tests on the batteries; and step 5, finely adjusting the rotating speeds and rotation directions of the two motors to keep the batteries in a set extruded state, and repeating the steps 3 and 4.

Further preferably, a specific method for measuring the thickness of the (N-1) extruded batteries in the step 3 is described as follows: setting that a first reflector is closest to a laser range finder, the distance from the first reflector to the laser range finder is c, the thickness of the clamping plates is d, a perpendicular distance from central points of reflection lenses to the bottom of a first layer of clamping plate is b, and a distance between central points of two adjacent reflectors is e; when the thickness of the extruded first battery is measured, introducing a direct current to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the first reflector, and abutting the first reflector with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; introducing a reverse direct current to other (N-2) electromagnets to enable the magnetic poles of the other (N-2) electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, clinging other (N-2) reflection lenses to the bottom plate; after laser emitted by the laser range finder is reflected by the first reflector, emitting a reflected ray to the bottom of a second layer of clamping plate after penetrating through a first through hole, at the moment, measuring an optical path distance Xi by the laser range finder, and obtaining the thickness YI=X1-(e+b+d) of the extruded first battery; when the thickness of the extruded second battery is measured, introducing a direct current to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the second reflector, and abutting the second reflector with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; introducing a reverse direct current to other (N-2) electromagnets to enable the magnetic poles of the other (N-2) electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, clinging other (N-2) reflection lenses to the bottom plate; after laser emitted by the laser range finder is reflected by the second reflector, emitting a reflected ray to the bottom of a third layer of clamping plate after penetrating through a second group of through holes, at the moment, measuring an optical path distance X2 by the laser range finder, and obtaining the thickness Y2=X2-Xi-d-e of the extruded second battery; deduced in such a manner, when the thickness of the (N-1)th battery is measured, introducing a direct current to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the (N-1)111 reflector, and abutting the (N-l)u1 reflector with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; introducing a reverse direct current to other (N-2) electromagnets to enable the magnetic poles of the other (N-2) electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, clinging other (N-2) reflection lenses to the bottom plate; after laser emitted by the laser range finder is reflected by the (N-l) reflector, emitting a reflected ray to the bottom of an Nth layer of clamping plate after penetrating through an (N-)th group of through holes, at the moment, measuring an optical path distance XN-1 by the laser range finder, and obtaining the thickness Ys1,1=Xs1,1 -XN,2-d-(N-1)e of the extruded 0\1-I)th battery.

Compared with the prior art, the present invention has the beneficial effects.

I. The test device with a multi-layer structure designed in the present invention can load the same mechanical load for lithium ion batteries in batches and can be matched with a battery tester to achieve the cyclic aging and other multi-abuse tests on the batteries in batches under the mechanical load.

2. By disposing the laser range finder, the reflection lenses, and an electromagnetic device on the test device in the present invention, the variation of the thickness of multiple batteries can be monitored in real time under the condition that only one laser range finder is used, and the variation of the thickness of each battery can be measured alone; and the test device is simple in structure and low in cost.

3. Grooves for placing thermocouples Or other types of temperature sensors are designed in each layer of clamping layer of the test device in the present invention, so that the temperatures of extruded surfaces of the batteries can be monitored in an aging test process; or non-extruded surfaces of the batteries can be provided with other types of temperature sensors, so that more comprehensive temperature monitoring is achieved.

4. The limiting holes are designed in each layer of clamping plate of the test device in the present invention and are matched with the polished rods in a base to ensure that all the layers are relatively parallel, thereby ensuring that mechanical loads borne by the batteries among all the layers are consistent.

5. According to the test device in the present invention, the servo motors and the lead screws arc matched to apply the mechanical loads to the batteries among all the layers, and thus, infinitely variable control on the mechanical loads can be achieved; and multiple batteries can be placed in the multi-layer structure, and therefore, the mechanical loads can be loaded to the batteries in batches, which is beneficial to the control on variables during batch tests.

6. Battery positioning slots are formed in each layer of clamping plate of the test device in the present invention, which can ensure that the placing positions of batteries in different test batches are the same, and thus, experimental variables are further controlled.

Brief Description of the Drawings

Fig. 1 is a main view of an aging test device for multiple batteries in an extruded state in the present invention; Fig. 2 is a top view of Fig. 1; Fig. 3 is a left view of Fig. 1; Fig. 4 is a sectional view of an axis passing through a lead screw in Fig. 3; Fig. 5 is a sectional view of a straight line parallel to the axis passing through the lead screw in Fig. 3; Fig. 6 is a top view of a first layer of clamping plate; Fig. 7 is a top view of a second layer of clamping plate; Fig. 8 is a schematic view achieved after a laser range finder and a second reflection lens rotate for 45 DEG; Fig. 9 is a schematic view showing a structure achieved when a reflection lens clings to a bottom plate; and Fig. 10 is a schematic view showing a structure achieved after the reflection lens rotates for 45 20 DEG.

Detailed Description of the Invention

The technical solutions in the embodiments of the present invention will be described clearly and completely as below with reference to the accompanying drawings in the embodiments of the present invention.

Embodiment 1: As shown in Figs. 1-10, provided is an aging test device for multiple batteries in an extruded state, including a base support 19, six clamping plates 2, two motors 9, a positioning plate 1, a pressure sensor 10, and a laser range finder 5.

The base support 19 is fixedly provided with a bottom plate 6 on which four polished rods 7 are vertically disposed, four limiting holes 8 and two positioning holes 20 are formed in each of the clamping plates, and both of the limiting holes and the positioning holes are unthreaded holes; all the clamping plates sleeve the polished rods via the limiting holes and are located above the bottom plate, and each of the limiting holes corresponds to one of the polished rods; seven clamping plates are stacked and are sequentially marked as a first layer of clamping plate, a second layer of clamping plate,..., a seventh layer of clamping plate from bottom to top, and batteries 3 are placed between two adjacent layers of clamping plates; the positioning plate 1 is located on the seventh layer of clamping plate, two threaded holes are formed in the positioning plate 1, and positions of the threaded holes correspond to positions of the positioning holes 20.

In the present embodiment, the clamping plates are rectangular plates, and the limiting holes are formed in the four corners of the rectangular plates.

In other embodiments, the number and shapes of the clamping plates and the number of the limiting holes are determined according to specific conditions.

The motors are fixedly disposed on the bottom plate, output shafts of the motors are vertical and upward, the output shaft of each of the motors is fixedly connected to a lead screw 4 vertically disposed, and the upper end of the lead screw extends into one of the corresponding threaded holes and is in threaded connection to the positioning plate 1 after the lead screw 4 penetrates through a group of positioning holes 20 corresponding to all the clamping plates.

As shown in Fig. 6, six through holes 11 of which the coordinates are sequentially marked as {(1, 1), (1, 2),..., (1, 6)1 are equidistantly formed in the first layer of clamping plate; as shown in Fig. 7, five through holes of which the coordinates are sequentially marked as ((2, 2), (2, 3),..., (2, 6)1 are equidistantly formed in the second layer of clamping plate; a through hole of which the coordinates are { (6, 6)1 is formed in a sixth layer of clamping plate; moreover, six through holes of which the coordinates are (1. 6), (2, 6),..., (6, 6) are concentrically disposed and are marked as a sixth group of through holes; five through holes of which the coordinates are (1, 5), (2, 5), (5, 5) are concentrically disposed and are marked as a fifth group of through holes; two through holes of which the coordinates are (1, 2) and (2, 2) are concentrically disposed and are marked as a second group of through holes; a through hole of which the coordinates are (1, 1) is marked as a first through bole; and in the coordinates of the above-mentioned through holes, the first numeral represents the number of layers of the corresponding damping plates, and the second numeral represents markers of the through holes in the layer of clamping plate.

The batteries 3 are incapable of shielding the through holes 11.

The pressure sensor 10 and the laser range finder 5 are disposed on the bottom plate 6, five reflection lenses 14 are equidistantly disposed on the bottom plate 11, and the pressure sensor 10 and the reflection lenses 14 are located between the bottom plate and the first layer of clamping plate; the five reflection lenses are sequentially marked as a first reflector, a second reflector,..., a sixth reflector; the lower ends of the reflection lenses 14 are hinged with the bottom plate 6 by a rotating shaft 18, the back of each of the reflection lenses is fixedly provided with a magnet 15, and the bottom plate 6 is provided with six electromagnets 16; each of the electromagnets 16 corresponds to one of the magnets 15; a limiting support 17 enabling a working surface of each of the reflection lenses and the bottom plate to form a 45-DEG included angle is disposed on each of the reflection lenses 14; the height of the pressure sensor is greater than the heights of the reflection lenses which are inclined for 45 DEG, as shown in Fig. 10. The height of the sensor is greater than the heights of the reflection lenses which are inclined for 45 DEG, that is, the pressure sensor is extruded after the first layer of clamping plate is acted by a pressure.

The first reflector corresponds to the first through hole, the second reflector corresponds to the second group of through holes,..., the sixth reflector corresponds to the sixth group of through holes.

For example, when an included angle formed by the second reflector and the bottom plate is 45 DEG, other five reflection lenses cling to the bottom plate, as shown in Fig. 9, a reflected ray obtained after laser emitted by the laser range finder is reflected by the second reflector penetrates through the second group of through holes, as shown in Fig. 8, wherein a dotted line is a light beam emitted by the laser range finder.

By disposing the above-mentioned test device in the present invention, six lithium ion batteries to be tested are placed into the device, a lithium ion battery is placed between the two adjacent clamping plates, mechanical loads may be uniformly applied to these batteries, the mechanical loads are adjusted by using the lead screws and the motors, and the types of the mechanical loads applied to the batteries are adjusted by adjusting the shape of each layer of the multi-layer structure.

In the present embodiment, positioning slots 12 are formed in the clamping plates 2, the batteries are placed into the positioning slots so as to be prevented from displacing after the mechanical loads are applied. Moreover, it is ensured that the positions of new batteries placed again are consistent to the original positions it is also ensured that the mechanical loads on all the batteries are consistent, and thus, the accuracy of test results is improved.

In the present embodiment, grooves 13 in which temperature sensors are disposed are formed in bottom plates of the positioning slots, and the temperature sensors are in contact with the surfaces of the batteries. By disposing the temperature sensors, the temperatures of the batteries are monitored while the mechanical loads are loaded to the batteries.

In the present embodiment, the limiting supports 17 are frames shaped like a Chinese character -Men" and are fixed to the bottom plate, and the reflection lenses 14 are abutted with limiting cross bars of the limiting supports when upwards rotating to form a 45-DEG included angle with the bottom plate.

In the present embodiment he motors 9 are servo motors.

Embodiment 2: Provided is a test method based on the above-mentioned aging test device for multiple batteries in the extruded state, including the following steps: step 1, six batteries to be tested are placed into the above-mentioned device, a battery is placed between two adjacent clamping plates, and the batteries are sequentially marked as a first battery, a second battery,..., a sixth battery from bottom to top; step 2, two motors with the same rotating speed and rotation direction are started at the same time, the motors drive lead screws to rotate, and then, a positioning plate is driven to move downwards to extrude the seventh layer of clamping plate, so that the seven clamping plates move downwards along the polished rods after being stressed to extrude the batteries, that is, mechanical loads are applied to the batteries; and meanwhile, the first layer of clamping plate transfers a pressure to a pressure sensor, the pressure sensor acquires a pressure signal to a control system in real time, and alter a pressure value acquired by the pressure sensor is equal to a set value, such an extruded state is maintained; step 3, the thickness of the six batteries under such mechanical loads is measured; it is set that a first reflector is closest to a laser range finder, the distance from the first reflector to the laser range finder is c, the thickness of the clamping plates is d, and a perpendicular distance from central points of reflection lenses to the bottom of the first layer of clamping plate is b; when the thickness of the extruded first battery is measured, a direct current is introduced to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the first reflector, and the first reflector is abutted with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; a reverse direct current is introduced to other five electromagnets to enable the magnetic poles of the other five electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, other five reflection lenses cling to the bottom plate; after laser emitted by the laser range finder is reflected by the first reflector, a reflected ray is emitted to the bottom of a second layer of clamping plate after penetrating through a first through hole, at the moment, an optical path distance Xi is measured by the laser range finder, and the thickness Nii----X1-(e b d) of the extruded first battery is obtained; when the thickness of the extruded second battery is measured, a direct current is introduced to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the second reflector, and the second reflector is abutted with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; a reverse direct current is introduced to other five electromagnets to enable the magnetic poles of the other five electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, other five reflection lenses cling to the bottom plate; after laser emitted by the laser range finder is reflected by the second reflector, a reflected ray is emitted to the bottom of a third layer of clamping plate after penetrating through a second group of through holes, at the moment, an optical path distance X2 is measured by the laser range finder, and the thickness Y2-X2-Xi-d-e of the extruded second battery is obtained; deduced in such a manner, when the thickness of the sixth battery is measured, a direct current is introduced to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the sixth reflector, and the sixth reflector is abutted with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; a reverse direct current is introduced to other five electromagnets to enable the magnetic poles of the other five electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, other five reflection lenses cling to the bottom plate; after laser emitted by the laser range finder is reflected by the sixth reflector, a reflected ray is emitted to the bottom of a seventh layer of clamping plate after penetrating through a sixth group of through holes, at the moment, an optical path distance X6 is measured by the laser range finder, and the thickness Y6-X6-Xs-d-5e of the extruded sixth battery is obtained; step 4, a battery tester is used to load electric loads to the six batteries under such mechanical loads in batches, and charging and discharging cycle or electric abuse is performed on the batteries to achieve multi-abuse aging tests on the batteries; and step 5, the rotating speeds and rotation directions of the two motors are finely adjusted to keep the batteries in a set extruded state, and the steps 3 and 4 are repeated. By repeated experiments, the accuracy of results arc guaranteed.

It should be understood that the specific embodiments described herein are merely intended to explain the present invention, rather than limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principle of the present invention should fall within the protection scope of the present invention.

Claims

Claims 1. An aging test device for multiple batteries in an extruded state, characterized by comprising a base support, N clamping plates, two motors, a positioning plate, a pressure sensor, and a laser range finder; the base support is fixedly provided with a bottom plate on which M polished rods are vertically disposed, M limiting holes and two positioning holes are formed in each of the clamping plates, and both of the limiting holes and the positioning holes are unthreaded holes; all the clamping plates sleeve the polished rods via the limiting holes and are located above the bottom plate, and each of the limiting holes corresponds to one of the polished rods; the N clamping plates are stacked and are sequentially marked as a first layer of clamping plate, a second layer of clamping plate,..., an Nth layer of clamping plate from bottom to top, and batteries are placed between two adjacent layers of clamping plates; the positioning plate is located on the Nth layer of clamping plate, two threaded holes are formed in the positioning plate, and positions of the threaded holes correspond to positions of the positioning holes; both of M and N are positive integers greater than or equal to 3; the motors are fixedly disposed on the bottom plate, output shafts of the motors are vertical and upward, the output shaft of each of the motors is fixedly connected to a lead screw vertically disposed, and the upper end of the lead screw extends into one of the corresponding threaded holes and is in threaded connection to the positioning plate after the lead screw penetrates through a group of positioning holes corresponding to all the clamping plates; (N-1) through holes of which the coordinates are sequentially marked as {( I, 1), (1, 2),..., (1, N-1)1 are equidistantly formed in the first layer of clamping plate; (N-2) through holes of which the coordinates are sequentially marked as {(2, 2), (2, 3) ..... (2, N-1)1 are equidistantly formed in the second layer of clamping plate; a through hole of which the coordinates are {(N-1, N-1)} is formed in an (N-1)th layer of clamping plate; moreover. N-1 through holes of which the coordinates are (1, N-1), (2, N-1),..., (N-1, N-1) are concentrically disposed and are marked as an (N-I)th group of through holes; N-2 through holes of which the coordinates are (1, N-2), (2, N-2),.. (N-2, N-2) are concentrically disposed and are marked as an (N-2)th group of through holes; two through holes of which the coordinates are (1. 2) and (2, 2) are concentrically disposed and are marked as a second group of through holes; a through hole of which the coordinates are (1, 1) is marked as a first through hole; the batteries are incapable of shielding the through holes; the pressure sensor and the laser range finder are disposed on the bottom plate, (N-1) reflection lenses are equidistantly disposed on the bottom plate, and the pressure sensor and the reflection lenses are located between the bottom plate and the first layer of clamping plate; the (N-1) reflection lenses are sequentially marked as a first reflector, a second reflector an (N-1)th reflector; the lower ends of the reflection lenses are hinged with the bottom plate, the back of each of the reflection lenses is fixedly provided with a magnet, and the bottom plate is provided with (N-1) electromagnets; each of the electromagnets corresponds to one of the magnets; a limiting support enabling a working surface of each of the reflection lenses and the bottom plate to form a 45-DEG included angle is disposed on each of the reflection lenses; the height of the pressure sensor is greater than the heights of the reflection lenses which are inclined for 45 DEG; and a probe of the pressure sensor is in contact with the bottom of a first clamping plate; the first reflector corresponds to the first through hole, the second reflector corresponds to the second group of through holes,..., the (N-1)th reflector corresponds to the (N-1)t group of through holes; and when an included angle formed by the (4-1)th reflector and the bottom plate is 45 DEG, other (N-2) reflection lenses cling to the bottom plate, at the moment, a reflected ray obtained after laser emitted by the laser range finder is reflected by the (NW' reflector penetrates through an 25th K) group of through holes, wherein k is a positive integer smaller than or equal to N-1.
2. The aging test device for multiple batteries in the extruded state of claim I, characterized in that positioning slots are formed in the clamping plates.
3. The aging test device for multiple batteries in the extruded state of claim 2, characterized in that grooves in which temperature sensors are disposed are formed in bottom plates of the positioning slots, and the temperature sensors are in contact with the surfaces of the batteries.
4. The aging test device for multiple batteries in the extruded state of claim 1, characterized in that the limiting supports are frames shaped like a Chinese character "Men" and are fixed to the bottom plate, and the reflection lenses are abutted with limiting cross bars of the limiting supports when upwards rotating to form a 45-DEG included angle with the bottom plate.
5. The aging test device for multiple batteries in the extruded state of claim 1, characterized in that the motors are servo motors.
6. A test method based on the aging test device for multiple batteries n the extruded state of any one of claims 1 to 5, characterized by comprising the following steps: step 1, placing N-1 batteries to be tested into the device of claims 1 to 4, placing a battery between two adjacent clamping plates, and sequentially marking the batteries as a first battery, a second battery,..., an (N-1)th battery from bottom to top; step 2, starting two motors with the same rotating speed and rotation direction at the same time, driving, by the motors, lead screws to rotate, and then, driving a positioning plate to move downwards to extrude N layers of clamping plates and the (N-1) batteries; acquiring, by a pressure sensor, a pressure signal to a control system in real time, and after a pressure value acquired by the pressure sensor is equal to a set value, maintaining such an extruded state; step 3, measuring the thickness of the (N-1) batteries under such mechanical loads; step 4, using a battery tester to load electric loads to the (N-1) batteries under such mechanical loads in batches, and performing charging and discharging cycle or electric abuse on the batteries to achieve multi-abuse aging tests on the batteries; and step 5, finely adjusting the rotating speeds and rotation directions of the two motors to keep the batteries in a set extruded state, and repeating the steps 3 and 4.
7. The test method of claim 6, characterized in that a specific method for measuring the thickness of the (N-1) extruded batteries in the step 3 is described as follows: setting that a first reflector is closest to a laser range finder, the thickness of the clamping plates is d, and a perpendicular distance from central points of reflection lenses to the bottom of a first layer of clamping plate is b; when the thickness of the extruded first battery is measured, introducing a direct current to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the first reflector, and abutting the first reflector with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; introducing a reverse direct current to other (N-2) electromagnets to enable the magnetic poles of the other (N-2) electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, clinging other (N-2) reflection lenses to the bottom plate; after laser emitted by the laser range finder is reflected by the first reflector, emitting a reflected ray to the bottom of a second layer of clamping plate after penetrating through a first through hole, at the moment, measuring an optical path distance Xi by the laser range finder, and obtaining the thickness Yi-Xi-(c+b+d) of the extruded first battery; when the thickness of the extruded second battery is measured, introducing a direct current to an electromagnet, of Which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the second reflector, and abutting the second reflector with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; introducing a reverse direct current to other (N-2) electromagnets to enable the magnetic poles of the other (N-2) electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, clinging other (N-2) reflection lenses to the bottom plate; after laser emitted by the laser range finder is reflected by the second reflector, emitting a reflected ray to the bottom of a third layer of clamping plate after penetrating through a second group of through holes, at the moment, measuring an optical path distance X2 by the laser range finder, and obtaining the thickness 1Y2-X2-X -d-c of the extruded second battery; deduced in such a manner, when the thickness of the (N-1)th battery is measured, introducing a direct current to an electromagnet, of which the magnetic pole is the same as the magnetic pole of a corresponding magnet, corresponding to the (N-1)th reflector, and abutting the (N-1)th reflector with a cross bar of a corresponding limiting support after upwards rotating for 45 DEG; introducing a reverse direct current to other (N-2) electromagnets to enable the magnetic poles of the other (N-2) electromagnets to be opposite to the magnetic poles of the corresponding magnets, and then, clinging other (N-2) reflection lenses to the bottom plate; after laser emitted by the laser range finder is reflected by the (N-1)th reflector, emitting a reflected ray to the bottom of an Nth layer of clamping plate after penetrating through an (N-1)th group of through holes, at the moment, measuring an optical path distance XN-i by the laser range finder, and obtaining the thickness YN-1=XN--XN-1-d-(}4-1)e of the extruded second battery.