How does the partial crush test lead to cell deactivation
How does the partial crush test lead to cell deactivation,
KC,
▍What is KC?
Since 25th Aug., 2008，Korea Ministry of Knowledge Economy (MKE) announced that the National Standard Committee will conduct a new national unified certification mark — named KC mark replacing Korean Certification during the time between Jul. 2009 and Dec. 2010. Electrical Appliances safety certification scheme (KC Certification) is a mandatory and self-regulatory safety confirmation scheme according to Electrical Appliances Safety Control Act, a scheme which certified safety of manufacture and sale.
The difference between mandatory certification and self-regulatory (voluntary) safety confirmation：
For the safe management of electrical appliances, KC certification is divided into mandatory and self-regulatory (voluntary) safety certifications as the classification of danger of product.The subjects of Mandatory certification is applied to electrical appliances which its structures and methods of application may cause serious dangerous results or obstacle such as fire, electric shock. While the subjects of self-regulatory (voluntary) safety certification is applied to electrical appliances which its structures and methods of application can hardly causes serious dangerous results or obstacle such as fire, electric shock. And the danger and obstacle can be prevented by testing the electrical appliances.
▍Who can apply for KC certification：
All legal persons or individuals both at home and abroad who are engaged in manufacturing, assembly, processing of electrical appliance.
▍Scheme and method of safety certification：
Apply for KC certification with product’s model that can be divided into basic model and series model.
In order to clarify model type and design of electrical appliances, an unique product name will be given according to its different function.
▍ KC certification for Lithium battery
- KC certification standard for lithium battery：KC62133:2019
- Product scope of KC certification for lithium battery
A. Secondary lithium batteries for use in portable application or removable devices
B. Cell is not subject to KC certificate whether for sale or assembled in batteries.
C. For batteries used in energy storage device or UPS (uninterruptible power supply), and their power which is greater than 500Wh are beyond the scope.
D. Battery whose volume energy density is lower than 400Wh/L comes into certification scope since 1st, Apr. 2016.
▍Why MCM?
● MCM keeps a close cooperation with Korean labs, such as KTR (Korea Testing & Research Institute) and is able to offer the best solutions with high cost performance and Value-added service to clients from the point of lead time, testing process, certification cost.
● KC certification for rechargeable lithium battery can be gained by submitting a CB certificate and convert it into KC certificate. As a CBTL under TÜV Rheinland, MCM can offer reports and certificates which can be applied for conversion of KC certificate directly. And the lead time can be shortened if applying CB and KC at the same time. What’s more, the related price will be more favorable.
Taiwan BSMI Group III stated in a document sent to the general BSMI testing laboratories on July 21, 2022, that a laboratory system management system will be implemented to strengthen the management of designated laboratories and to keep track of the testing progress and situation. The relevant implementation is as follows.From September 1, 2022, designated laboratories of electronic commodity inspection including voluntary product inspection and others need to:Type test reports need to use the BSMI designated report number, the laboratory’s own report number can choose to retain, but the two report numbers need to have a unique correspondence.The laboratory is required to submit a case acceptance to the BSMI Designated Laboratory Application System within 1 day of receipt of the sample.From the management methods to be implemented by the third group, BSMI has more and more stringent requirements for each laboratory’s test capacity capacity, test cycle, and test records. The later development of management methods will inevitably have an impact on sample arrival time and test time management, and MCM will keep observation and update timely.
Crush is a very typical test to verify the safety of cells, simulating the crush collision of cells or end products in daily use. There are generally two types of crush tests: flat crush and partial crush. Compared to the flat crush, the partial indentation caused by a spherical or cylindrical indenter is more likely to cause the cell ineffective. The sharper the indenter, the more concentrated the stress on the core structure of the lithium battery, the more serious the rupture of the inner core, which will cause deformation and displacement of the core, and even lead to serious consequences such as electrolyte leakage or even fire. So how does crush lead to the deactivation of the cell? Here introduce you to the internal structure evolution of the core in the local extrusion test.
