Testing Chambers Knowledge

  Drop Test National standard GB31241GB/T18287 requirements: fully charged lithium-ion battery square battery six sides of each side fell once, fell to the cement ground, a total of six drops with a height of 1 meter; The positive and negative poles of the circular battery each fell once and the cylinder surface fell four times to the top of the 1 meter plank. After the end of the free fall, after half an hour of placement, test the voltage and internal resistance, the open circuit voltage is not less than 90% of the initial voltage, no leakage, no fire and no explosion.  Drop testing examines possible drops in the shipping environment or in customer use; From the safety point of view, it is to detect the weld sealing performance of the battery. Using this test method, increase the voltage, internal resistance and quality before the test falls; After 6 falls, measure the voltage, internal resistance, and quality again according to the voltage, internal resistance, and quality ...

  Since the mass production of lithium battery, it has rapidly led the trend in the field of battery with its excellent performance such as high energy ratio, long cycle life and high electrode voltage. It has an absolute advantage in mobile phone, computer and other industries, and has become one of the important research topics of new energy vehicles. In order to meet the requirements of the market for high storage energy, enterprises increase the specific energy research and development of a single battery. Although it can improve the standby time of mobile phones, it also makes the volume energy density of a single battery higher and higher, and its security problems become more and more prominent.  The main restrictive factor for the commercial promotion of high-capacity and lithium-ion batteries is safety, and there are many potential safety hazards. In order to analyze and solve such problems, several international safety standards have been proposed, such as   IEC...

  Lithium-ion batteries are widely used in various fields such as mobile devices, energy storage and new energy vehicles with their advantages of high cycle life than energy, but compared with other types of batteries. Their safety is the main problem that needs to be solved. Lithium-ion batteries produce safety problems mainly through heat generation, and finally the way of thermal runaway embodiment and the reasons for the formation of thermal runaway are mainly short circuit, connection failure, high temperature baking, immersion in water, etc., of which short circuit is the most common cause of thermal runaway Short circuit is divided into external short circuit and internal short circuit, external short circuit can be controlled through the protection of auxiliary components and the optimization of the strategy while the internal short circuit is difficult to effectively control.  In this paper, the systematic study of the simulation method of internal short circuit princ...

  3.Protection of hardware facilities The elements of personnel protection have been listed above. It is not difficult to prepare these equipment. The important thing is to use appropriate equipment on appropriate occasions. Laboratory management should standardize this effective document, remove the paralytic thought of test operators and maintain preventive awareness. Regular drills may be as important as configuring these equipment.   The test process of rolling test and impact ( impact ) test in abnormal work ( abuse ) test may produce violent response. The former is rolled with a force equivalent to 1000 times the self weight of the sample: the impact test is to drop a 9.1kg weight freely from 610mm and impact the sample.   The relatively closed steel  test chamber  has good protective effect, but it will be inconvenient because the line of sight is blocked in the test. The observation window can be opened with explosion-proof glass and protective net. The ...

  Basic contents of protection Compared with other types of power batteries, electric vehicle power lithium-ion battery is more prone to unsafe conditions such as combustion and explosion due to its electrochemical characteristics, structural characteristics and application environment, such as no special attention in the test process. During the  test , especially in the test with high severity. The safety protection of laboratory is an unavoidable reality.   In order to facilitate the description, the protective measures are divided into hardware facility protection of test personnel and equipment (for the protection of unsafe state caused by leakage, rupture, combustion and explosion) and software early warning / control protective measures for the purpose of avoiding state. Basic design of protection. Both aspects shall be considered comprehensively, and both shall be appropriate and effective. In addition, considering the protected objects, they can be roughly divide...

  2.1.2 Overcharge / overdischarge test In order to evaluate the function of overcharge / overdischarge protection system, it may occur when the battery charging or discharging exceeds the limits recommended by the manufacturer, such as charger failure. Almost all standards and regulations stipulate this test item The important safety hazards during overcharge are electrolyte decomposition, cathode and anode breakdown, diaphragm degradation and exothermic decomposition of lithium coating, resulting in battery overheating and heat out of control. If sufficient temperature is reached (e.g. 200 ℃), the fluorinated adhesive will undergo exothermic reaction with carbon lithium. The factors affecting the test results include the charging rate and the final SOC. For overcharge test, charge the battery according to the charging current specified in the standard until the set end charging conditions (such as 200% SOC, 130% SOC, etc.) are reached, or the protection device is used (such as di...

  Power lithium-ion batteries must pass a series of safety tests before they can be used in electric vehicles. These safety tests are to understand and identify the potential weakness and vulnerability of the battery under abnormal conditions, and determine the performance of the battery under severe conditions.  Due to the limitation of space, the author only analyzes and summarizes the international standards and regulations for electrical safety and harsh environmental testing of lithium-ion batteries for electric vehicles, and discusses the problems existing in the standards.   1. Overview of domestic and foreign standards and regulations Important international standards related to the safety and harsh environmental testing of lithium ion battery gas for electric vehicle power include:   IEC62660-2:2011 lithium ion power battery Part 2: reliability and abuse test;   ISO6469-1:2019 safety requirements for electrically driven road vehicles, Part 1: rechargeab...