Safe and long life energy storage lithium ion batteries or preferred lithium iron phosphate batteries

 

” Security” is a topic that cannot be avoided in the development of energy storage. In recent years, fire accidents have occurred from time to time, ranging from energy storage power stations to new energy vehicles.

In addition to the defects of the battery itself, these accidents also have many system problems that need to be solved urgently.

Focusing on the recent battery fire accidents, this edition will start thinking about ensuring the safety of energy storage from multiple dimensions such as basic research, technology development, design and manufacturing.

Potential factors for the “short-lived” of lithium-ion batteries have been discovered. With the help of new electrode materials and interface design, the performance of electrodes can be improved, and the use of nanosystem engineering concepts can improve the lithium storage performance of materials… Recently, regarding energy storage batteries, especially lithium-ion batteries More and more research.

Although the research methods and paths may be different, the research results have a common propaganda point, that is, high security.

Energy storage safety is a topic that cannot be avoided in the development of energy storage. The current energy storage safety problem mainly comes from electrochemical energy storage, and battery packs (stacks) are one of its biggest safety hazards.

According to the “2020 Energy Storage Industry Application Research Report” (hereinafter referred to as the “Report”), in 2019 alone, China’s energy storage projects added a total of 1228.4 MW of newly installed capacity, of which 678.4 MW of electrochemical energy storage projects accounted for First, it is as high as 54.5%.

As of the end of 2019, the installed capacity of lithium-ion batteries accounted for 82.4% of the installed capacity of electrochemical energy storage.

However, the safety of energy storage is not only caused by batteries. “China Science Daily” learned in an interview that energy storage safety is a systemic problem, and a problem in a certain link may cause a fire.

Thinking after the fire accident

Since the accident of fire at 23 energy storage power stations in South Korea in August 2017, energy storage safety issues have been plagued by the industry. “Report” believes that this is related to the mainstream products of ternary lithium batteries by major Korean companies.

According to Jiang Weiliang, a professor-level senior engineer of the Energy Storage Application Branch of the China Chemical and Physical Power Supply Association, the current major energy storage companies in the world are mainly traditional battery companies, and the technology is basically based on two major factions, namely, the Japanese and Korean ternary lithium battery system and the Sino-US phosphoric acid Lithium iron battery system.

But it does not mean that lithium iron phosphate batteries are absolutely safe. In early August 2018, a lithium iron phosphate battery container caught fire and burned in an energy storage project in Jiangsu, my country, but the cause of the fire has not yet been announced.

According to Duan Qiangling, associate professor of the State Key Laboratory of Fire Science at the University of Science and Technology of China, during the use of lithium batteries, lithium ions are inserted and pulled out to release energy.

If used improperly, conditions such as overcharging, high temperature, collision, etc. may induce thermochemical reactions inside the battery, leading to thermal runaway.

“If thermal runaway occurs in the battery module, it will cause a fire accident in the system.”

It is worth noting that thermal runaway will produce toxic and combustible gases, and fire fighting with lithium-ion batteries is more difficult, which brings challenges to firefighting.

In recent years, the application of electrochemical energy storage technology has accelerated, and product commissioning cycles have become shorter and shorter. Under the circumstances that the safety standard system is not yet complete and the regulatory mechanism has not been established, energy storage safety accidents in various countries have occurred from time to time.

“These key issues must be addressed squarely.”

The energy storage system must use its own protection measures to deal with the abnormal conditions of the energy storage power station in a timely manner to minimize the safety risk of the energy storage system.

The battery itself becomes the core of safety

In response to fire accidents in energy storage power stations, South Korea established an expert investigation team to summarize the causes as defects in battery systems, imperfect protection systems for electrical failures, inadequate management of the operating environment, and lack of an integrated management system for energy storage systems.

Among them, battery system defects may be one of the main factors causing fires.

Drawing on the classification of safety incentives in the Korean Energy Storage Accident Investigation Report, the Guangzhou Institute of Energy Research of the Chinese Academy of Sciences believes that the causes of energy storage safety accidents are divided into four categories: battery body, external stimulus, operating environment and management system.