What Lithium batteries, IEC standards are

April 14, 2021

Latest company news about What Lithium batteries, IEC standards are

 

1 Introduction
Secondary lithium battery production in Japan's long been stereotyped mode. However, in recent years embarked on the work of cylindrical and the Ling cylindrical battery. International electric technology began to prepare a series of new battery standards, including safety standards. On the one hand more and more important for larger capacity caused by the accident of some second-generation lithium battery security to ensure not to reproduce the past problems in the future.
Security issues for secondary lithium batteries, you need to study the safety of the battery charging technology, as well as rechargeable batteries discharge of security technology.


2 Overview
This approach describes the minimum safety standards to be completed by the battery manufacturer. The approach is applicable to cylindrical spiral electrode and the hierarchical structure and Ling cylindrical battery and the battery is to power as a small hand-held tools, the capacity range of 100 5000mAh The guidelines apply equally to the battery factory has been producing battery in the future will begin to apply.
This approach assumed a variety of unsafe mode assessment test in order to determine the level of security and quality.
Second, the second-generation lithium battery assessment guidelines
(1) the purpose of battery
In this guide for sampling battery is a rechargeable lithium batteries for small portable tools.
(* 1): In these examples, energy refers to the tools mobile electrical energy, and therefore does not include backup memory.
The past, the widely used lithium batteries on the market were not included in the manual, because those battery model is smaller, by the current limit of the capacitance is also smaller, and therefore, the risk coefficient is considered in terms of safety performance can be ignored.
In this manual, the requirements of secondary lithium batteries are the following classification:
(1) as the portable electric tools, electric energy
(2) of the spiral electrode and the hierarchical structure of cylindrical and Ling cylindrical battery
(3) cylindrical battery size between D and N
(4) Link cylindrical battery capacity of 100 to 5000mAh
(5) can only batteries, including the collection of batteries
(* 2) a collection of batteries is included in this brochure collection of batteries in the future the appropriate stage of preparation at this stage, the collection of batteries more difficult requirements or that its shape, structure, and size.
(2) manual essentials
The safety assessment process is arranged in the normal use of the battery, or in the method of operation can be expected of them, or in the operation of the special circumstances, such as the charger failure, battery tool failure. The program also introduces some misconduct can be avoided in normal use. safety assessment is divided into the following three categories, each of which has detailed the steps:
(1) The electrical properties
(2) testing of mechanical properties
(3) environmental test
To determine the standard of the test results does not occur according to the risk of endangering human body in these steps for each select five test batteries for the sample, which is given to this figure is sufficient to determine the degree of battery safety.
(4) assess the Test Project
4.1 (a) electrical test
Temperature of the test item charge status of battery condition assessment test method standards
External short-circuit is fully charged, just finished production of the battery at room temperature 60 ° C the resistance is less than 50mΩ wire short-circuit for more than six hours at the poles did not explode, no fire phenomenon
Forcibly discharge a fully charged battery has just finished production to normal room temperature forced the depth of discharge recommended by the manufacturers current computing capacity of 250% * in the testing process to meet safety or protection function, you can terminate the test did not explode, no fire phenomenon
Continuous charge and fully discharge the battery has just finished production at normal room temperature according to the manufacturer's recommended method of charging, and at the specified voltage for 28 days did not explode, no fire, no splitting phenomenon phenomenon
Overcharge completely discharge the battery just finished production of normal room temperature, the current recommended by the manufacturers charge to 250% of the computing capacity. * If in the testing process to meet safety or protection function, you can terminate the test did not explode, no fire phenomenon
High current charging completely discharge the battery has just finished production at normal room temperature three times the current according to the manufacturer's recommended charge current to charge the battery did not explode more than 100% of computing capacity, no fire phenomenon
4.1 (2) I mechanical performance test
Temperature of the test item charge status of battery condition assessment test method standards
Vibration is fully charged or fully discharged battery has just finished production to normal room temperature, the battery in the XYZ three directions of vibration of 90-100 minutes, with an amplitude of 0.8mm, the frequency is 10HZ, the rate of change of the frequency 1HZ/min after the test, complete discharged battery will be recharged to full capacity recommended by the manufacturers. no explosion, no fire, no deformation phenomenon
2. Acceleration is fully charged or fully discharged battery has just finished production normal room temperature, time acceleration in the initial 3 milliseconds average acceleration of 75g (g is the acceleration due to gravity units), reached its peak of 125-175g in each an XYZ each other perpendicular to the direction of vibration tests, the fully discharged battery will be charged to the manufacturers recommended capacity. no explosion, no fire, no deformation of the phenomenon
3. Drop is fully charged or fully discharged battery at normal room temperature 10 to the concrete floor from 1.9m high free fall has just finished production after the test, a fully discharged battery will be charged to the manufacturers recommended capacity did not explode. the phenomenon of fire
4.1 (2) II Test Project test method standard charging temperature assessment of the status of battery condition
Nail through the battery is fully charged batteries at normal room temperature with a diameter of 2.5 to 5 mm nails through a battery of vertical spindle * a nail into the battery within 6h. Did not explode just finished production did not fire phenomenon
Squeeze fully charged battery has just finished production at normal room temperature of the battery between the two flat iron to the longitudinal axis of the heart of the battery in parallel with the flat iron, to give the battery exert 13kN pressure did not explode, no fire phenomenon
The impact completely charge the battery has just finished production at normal room temperature, a cylindrical wooden stick (diameter 7.9mm) across the top of the battery and battery vertical spindle vertical .9.1 kg considerable weight from 61cm height of fall down. Did not explode. the phenomenon of fire
7.10m falling completely charge the battery has just finished production to normal room temperature from a 10m high any battery fell to the concrete floor. No explosion, no fire phenomenon
4.1 (3) Ⅰ environmental performance test
Temperature of the test item charge status of battery condition assessment test method standards
A high temperature storage is fully charged the battery (a) has just finished production to five hours after the battery on the storage temperature of 100 ° C oven temperature of 20 ° C place to place 24h (b) stored for 30 days in the 60 ° C oven battery will be placed in a temperature of 20 ° C, place 24 hours did not explode, no fire phenomenon
Heat conflict fully charged battery has just finished production at -20 ° C and 40 ° C within 2 hours after 10 continuous cycle of the battery moved from -20 ° C to 60 ° C, place, and replace the time within five minutes explosion, no fire, no damage, no deformation of the phenomenon
Low voltage fully charged battery at room temperature just finished production of the battery placed at an absolute pressure equal to or less than 11.6kpa for six hours and did not explode, no fire phenomenon
Standard Test Method of test item 4.1 (3) II environmental performance test (misconduct) charge state of the battery conditions of temperature assessment
Heat to heat up fully charging the battery has just finished production of the battery into the oven heating rate of 5 ± 2 ℃ / min until 130 ℃. Battery and then place the oven for about 60 minutes. No explosion, no fire phenomenon
Fall to the water fully charged battery at room temperature just finished production of the battery immersed in water (room temperature) 24 hours did not explode, no fire phenomenon
Defined
Fully charged: computing capacity to achieve specified by the manufacturer, charge the battery manufacturers recommend charging conditions (current, voltage, temperature, time, etc.), and time requirements of the battery is charged within a week.
Fully discharge: the discharge under the conditions recommended by the manufacturer (including the current, temperature, etc.), the specified discharge voltage of the battery discharge time requirements of the battery within one week after discharge.
Just finished production of the battery: the requirements of the battery is less than a month after production, and to accept that less than XX charge-discharge cycle.
Battery cycle: According to the manufacturers recommended conditions, the battery for charging, discharging, and battery discharge capacity specified by the manufacturer of computing capacity decreased by 40-60%.
Indoor temperature: In the test, room temperature refers to 20 ± 5 ° C, which is the usual room temperature, this setting is to be based on a simple test environment.
Explosion: explosion of the battery internal endoplasmic scattering or the part of the battery casing is cracked and cause an explosion or damage.
Fire: fire is a fire caused by spontaneous combustion or ignition of the internal battery.
Safety valve operation: The meaning of the safety valve operating means exhaust the battery during normal use (the battery voltage release to the outside world).
Deformation: deformation of the battery due to external pressure or internal pressure caused by the shape of visual deformation.
4.2 Number of tests
Assess the safety standards in the standard test, the following number is required for the purposes of each test the number of project requirements: n = 5
4.3 explained
4.3.1 The electrical performance test
A. External short circuit
When the anode, cathode both ends of the short-circuit (a wire or metal resistance), can be predicted that the risk of battery will be a sudden rise in temperature, due to current flow and battery temperature if the temperature exceeds the capacity of battery , the battery will explode or catch fire.
This test is to assume that the battery in the handling or use of the method does not properly cause the battery external short circuit, so you want to test the temperature set at 60 ° C, is to ensure that the battery under the thermostat due to external short circuit and heat will remain in a safe state. this temperature requirement is in accordance with the UL `s external short circuit (UL1642) resistor (50mΩ) is specified by the the Japanese IEC National Committee (TC35/WG8) estimates.
(2) forced discharge (reversible process)
Battery due to the external forced discharge or wrongly forced reverse charge arising from the foreseeable risk: The battery is a normal chemical reaction occurs, leading to internal pressure, the temperature rises if the operation is excessive, the battery will be an explosion or fire.
This test is based on the assumption that such a situation: the battery is a mistake to reverse connected to a charger, or a combination of batteries, a battery low tolerance, then the combination of battery discharge, the support of low-capacity battery will force discharge (when the old and new batteries or different battery capacity in a battery box will appear in this case) the current and recommended by the manufacturer in accordance with the UL `S forced discharge test conditions, the battery discharge calculation for more than 250% of capacity .
When the battery has a safety, the protection performance, the current did not change because of these features, you can specify the logo on the battery, and can not continue to test.
(3) continuous charge
When restrictions than the battery can withstand continuous battery charging, can be predicted that the risk of excessive battery charging, increased intraocular pressure leading to electrolyte decomposition.
If the internal pressure exceeds a certain limit, the battery will explode.
This test assumes that the battery is connected to the charger to normal charging.
The continuous charging time scheduled for one month after the battery fully charging is finished, the normal action of the charger according to the design value less current time as a month, so that a full battery of continuous charging.
(4) charging excessive
Caused by charging excessive voltage rise than the battery can withstand limit, foreseeable risk of elevated lead normal chemical reaction or temperature heat: the battery voltage while charging a result, the battery will explode or catch fire.
This test assumes that such a situation: the charger is not functioning properly, especially its voltage control circuit is out of control.
Charger current control is assumed to be normal operation, thus current value as recommended by the manufacturers, but the charge capacity of 250% of the computing capacity to consider than the battery to withstand limited overcharge to ensure safety.
If the battery has security protection features, the current does not change, to indicate its logo, the tests also do not need to.
(5) high-current charging
When the battery charge because of the great current, can be predicted that the risk of temperature rise due to Joule heating if the temperature rises above permissions, the battery will explode, fire.
This test assumes that such a situation: The charger does not operate normally, in particular, the charger control settings out of control, in this test, the current is set to manufacturers to provide three times the current value (this value has reached the limit), Because even if the current controller failure because the internal resistance of the charger and the output capacity of reason, will not let a large current through.
And the charge capacity was designated as 100%, because this test is to examine the impact of a large current flows.
If the battery has security protection features, the current does not change, to indicate its logo, the tests also do not need to.
4.3.2 Ⅰ, mechanical performance test
(1) Vibration
Foreseeable risk of vibration when the battery is: the battery inside the connecting piece broken off from the connection point or the active material loss, resulting in the electrode in direct contact (short circuit), this reaction will be accelerated, and more than a certain limit, the battery due to internal pressure and an explosion or fire.
This test assumes that such a situation: the batteries in the transportation or improper user by vibration. This test method with reference to other standards, such as: UL, DOT, LATA.
The test to be scheduled for the fully discharged state is because the electrode is fully discharged state to move more easily, so the battery is more easily damaged when the vibration, and then charge the battery after the test, the damage is more obvious.
2 Acceleration
When the battery is affected by the impact, the same as in the example of the foreseeable risk and vibration.
This test is to assume that the battery subject to the risk of bumps during transport or due to user error batteries continue to fall.
This test is a reference to the DOT, LATA standard
If the battery has security protection features, the current does not change, to indicate its logo, the tests also do not need to.
3. Fall
A high degree of alleged battery drop could foresee the risk of battery vibration example. This test is based on the assumption that because a person's mistakes caused by the battery drops, the battery dropped 1.9m, this high is just ordinary people handle to lift the height.
If the battery has security protection features, the current does not change, to indicate its logo, the tests also do not need to.
The 4.3.2i errors behavioral tests
Four nails penetrate the cell by mistake a nail wrong through the battery will be connected to the positive and negative, leading to the external short circuit, the battery will heat explosion, fire due to a sudden reaction to produce.
This test assumes a situation: put the battery box, false nails penetrate the cell, or assuming that the internal short-circuit conditions to achieve the safety assessment.
In this manual, these tests are assumption is not correct behavior or short-circuit.
5 Squeeze
When the battery is subject to strong pressure and squeeze foreseeable risk of positive and negative space narrowing, and positive and negative may be in direct contact within a short circuit caused the battery could explode or catch fire.
This test assumes that the battery is under strong to be squeezed, such as cars. In this test, the extrusion conditions of the car load of 13kN is feasible, and by reference to UL1642.
6 Impact
Foreseeable risk due to gravity, battery by a sudden impact or drop considerable weight of material to the battery: the battery internal short circuit occurs.
This test assumes that the objects of a considerable weight drop in the battery, the object will give a powerful impact on a part of the battery to the test with reference to the UL.
7.10M fall
When the battery is falling down from a high place, the foreseeable risk: the impact of falling, the batteries have been squeezed, knot battery explosion or fire.
This test assumes that the battery from a high place such as roof or room windows.
In this test, the battery is dropped height set to 10M, this highly than the general windows of the house falling down even more serious.
4.3.3 Ⅰ environmental test
(1) high temperature storage
When the battery is incorrectly placed in the hot areas can be predicted that the risk of: the battery gets hot due to temperature, the polymer partition between the positive and negative integration, you can not separate between the two poles, results, due to the bipolar contact short circuit., Battery internal sudden reaction, if overheated, the battery will explode or ignite.
This test assumes that such a situation: When the battery due to external high temperature heat or the battery is set in the car dashboard, direct sunlight, heat, or temperature control is set to failure, leaving the indoor temperature in the summer by.
2-rise heat
When the risk of battery after a very powerful and rapid temperature changes can be expected: due to temperature changes and the impact of polymer composition, polymer and metal components of deformation or damage due to different coefficient of expansion.
This test assumes that such a situation: the battery in a very short time after a rapid temperature changes, such as the battery suddenly moved from outside to indoors, especially close to the room next to the fire source, or move from indoor to outdoor in the winter.
In this test in accordance with MIL and JIS standards, the exchange of time-less than 15 minutes.
3 low pressure
When the battery in the high altitude, in a very low environmental stress, such as air transport, the foreseeable risk: due to sealing part is damaged battery internal substances blasting or friction, resulting in an explosion or fire.
This test assumes that the transport of the battery on the plane was not pressurized, at 50,000 feet quite a high level of low-pressure environment.
The test with reference to the following standards: DOT, ICAO and LATA.
4.3.3 II improperly testing
When the battery is overheating, it is foreseeable risk: positive and negative polymer partition integration of the poles can not be separated from contact with each other, the results of the reaction, the battery will explode or ignite.
In this test, it is assumed that the battery was placed near a heat source, or is not correct behavior, such as the battery on the dashboard of the car under direct sunlight or test control settings failure thus indoor temperature.
This test will be the temperature set to 130 degrees to take into account the unusual circumstances, such as temperature control settings failure temperature is below 120 degrees.
5 fall in the water
When the risk of battery immersed in water, can be expected: the positive terminal of the high-voltage battery dissolution reaction, then, the tightness of the battery is damaged, water entered the battery and battery reacts, the battery due to heat generated by an explosion or fire.
This test is the assumption that the because errors battery into the water.