How to ensure the intrinsic safety of lithium-ion batteries,
Lithium Ion Batteries,

▍What is CTIA CERTIFICATION?

CTIA, the abbreviation of Cellular Telecommunications and Internet Association, is a non-profit civic organization established in 1984 for the purpose of guaranteeing benefit of operators, manufacturers and users. CTIA consists of all U.S. operators and manufacturers from mobile radio services, as well as from wireless data services and products. Supported by FCC (Federal Communications Commission) and Congress, CTIA performs a large part of duties and functions that were used to be conducted by the government. In 1991, CTIA created an unbiased, independent and centralized product evaluation and certification system for wireless industry. Under the system, all wireless products in consumer grade shall take compliance tests and those complying with the relevant standards will be granted to utilize CTIA marking and hit store shelves of North American communication market.

CATL (CTIA Authorized Testing Laboratory) represents labs accredited by CTIA for testing and review. Testing reports issued from CATL would be all approved by CTIA. While other testing reports and results from non-CATL will not be recognized or have no access to CTIA. CATL accredited by CTIA varies in industries and certifications. Only CATL which is qualified for battery compliance test and inspection has access to battery certification for compliance to  IEEE1725.

▍CTIA Battery Testing Standards

a) Certification Requirement for Battery system Compliance to IEEE1725— Applicable to Battery Systems with single cell or multiple cells connected in parallel;

b) Certification Requirement for Battery system Compliance to IEEE1625— Applicable to Battery Systems with multiple cells connected in parallel or in both parallel and series;

Warm tips: Select above certification standards properly for batteries used in mobile phones and computers. Do not misuse IEE1725 for batteries in mobile phones or IEEE1625 for batteries in computers.

▍Why MCM？

● Hard Technology: Since 2014, MCM has been attending battery pack conference held by CTIA in US annually, and is able to obtain latest update and understand new policy trends about CTIA in a more prompt, accurate and active way. 

●Qualification: MCM is CATL accredited by CTIA and is qualified to perform all processes related to certification including testing, factory audit and report uploading.

At present, most of the safety accidents of lithium-ion batteries occur due to the failure of the protection circuit, which causes the battery thermal runaway and results in fire and explosion. Therefore, in order to realize the safe usage of lithium battery, the design of protection circuit is particularly important, and all kinds of factors causing the failure of lithium battery should be taken into account. In addition to production process, failures are basically caused by changes in the external extreme conditions, such as over-charge, over-discharge and high temperature. If these parameters are monitored in real time and corresponding protective measures will be taken when they change, the occurrence of thermal runaway can be avoided. The safety design of lithium battery includes several aspects: cell selection, structural design and functional safety design of BMS.There are many factors affecting cell safety in which the choice of cell material is the foundation. Due to different chemical properties, the safety varies in different cathode materials of lithium battery. For example, lithium iron phosphate is olivine-shaped, which is relatively stable and not easy to collapse. Lithium cobaltate and lithium ternary, however, are layered structure that is easy to collapse. Separator selection is also very important, as its performance is directly related to the safety of the cell. Therefore in the selection of cell, not only detection reports but also manufacturer’s production process, materials and their parameters shall be considered.Insulation requirements generally involve the following aspects: Insulation between positive and negative electrode; Insulation between cell and enclosure; Insulation between the pole tabs and enclosure; PCB electrical spacing and creepage distance, internal wiring design, grounding design, etc.