China urges maritime safety review of lithium battery shipping

China has called on the International Maritime Organization to consider adjusting safety rules for transporting electric vehicles at sea amid a rising number of lithium-ion battery fire incidents.

China has submitted fire-fighting proposals in line with the International Convention for the Safety of Life at Sea (SOLAS) following "frequent" incidents involving electric vehicle battery fires, the International Maritime Organization (IMO) said in a bulletin on February 22.

China’s proposals include “enhanced protection” for ships’ automatic fire-fighting systems, more video surveillance of cargo, new rules governing the ro-ro spaces separated by vehicles on ships, and a review of protective clothing requirements for firefighters, among other requirements.

The IMO’s Maritime Safety Committee (MSC) will discuss the proposals in April 2022.

Review

“The increasing demand for shipping large quantities of various new energy vehicles, including lithium-ion battery vehicles – and reports of several major fire incidents on ships carrying lithium-ion battery vehicles – remind the international maritime community of the special safety risks of ships carrying new energy vehicles,” according to a Chinese submission to MSC.

The document urges the safety board to comprehensively review existing regulations — claiming that existing fire extinguisher systems are inadequate to handle hybrid vehicle transports, such as electric vehicles carried alongside alternative fuel vehicles .

China said it had tested the efficacy of gas fire-extinguishing systems in enclosed spaces on various electric vehicle models using lithium-ion batteries.

"In repeated tests, the flames on the battery surface were quickly extinguished after the release of the carbon dioxide fire extinguishing agent, but then reignited and were accompanied by a gas explosion."

Thermal runaway

“This is because it is difficult to prevent thermal runaway propagation between battery cells or modules, and the CO2 cooling effect is not strong enough to suppress thermal runaway reactions inside lithium-ion batteries.”

"At the same time, the flammable gases released by thermal runaway accumulated... forming an explosive gas environment. The loss of airtightness in the space and the entry of fresh air from the outside were also one of the reasons for the re-ignition."

Experience shows that fires in new energy vehicles may take longer to extinguish than those in fuel vehicles. Without "effective measures to isolate new energy vehicles... the fire may spread to other decks more quickly."

The newspaper said water spray systems were effective in suppressing individual electric vehicle fires but had limited impact on extinguishing fires that spread to other vehicles stored nearby, which then "had to be left to burn" or extinguished through "manual firefighting."

(Original text from: Energy Storage Magazine, Global Energy Storage Network, New Energy Network Comprehensive).