Safety concerns persist for lithium-ion battery storage. The electrodes can decompose at elevated temperatures and under overcharging or discharging conditions. At short to moderate periods of storage durations, lithium-ion batteries are the most cost-effective. These batteries are highly configurable, wherein modules can be arranged to obtain different power ratings and voltage specifications.
Listed below are the key weaknesses of lithium-ion batteries for underwater applications, as identified by GlobalData.
Thermal runaway, fire and explosion risks
In terms of fire risk, lithium-ion batteries are currently encountering serious fire safety concerns in a variety of industries, including the consumer electronics, automotive, aviation, and marine sectors. This has driven research and development efforts to refine the technology and increase safety levels, particularly concerning fire.
In particular, fire safety on manned underwater vehicles is crucially important. The UK Ministry of Defense (MoD) reported 266 fire incidents on its nuclear submarines in the last 25 years, 20 of which required significant onboard resources to contain. In the last six years, the Indian Navy has suffered four serious fire or fire safety system related incidents on their conventional submarines, claiming a total of 41 lives.
The most catastrophic LIB failure involves uncontrolled temperature increase within a cell due to battery failure leading to self-sustaining, exothermic chemical reactions that cause further heat release, breakdown of the cell, and sometimes explosion. This type of failure, or thermal runaway, is initiated by overheating the cell and or its components. Most critically, particularly for a submarine, the rapid release of thermal energy can heat neighbouring cells causing a cascade of thermal runaway failures throughout the entire battery bank. Thermal runaway can spread from one cell to the next quickly leading to a catastrophic fire. Companies are working with industries and universities and are testing their LIB solutions to provide safe and reliable power storage.
The high energy content, combined with extreme charging and operational patterns, represents new challenges about safety, integration, and service life. To avoid accidents and unwanted incidents that may have significant safety and cost implications – and potentially halt the development of these technologies – the battery-related systems must be verified and validated according to “best practice”. This is particularly vital in light of unwanted events, such as the explosion of a maritime battery system under test in Sweden and the 2016 recall of the Samsung Galaxy smartphone from the market.
This is an edited extract from the Lithium-ion Batteries for Underwater Applications – Thematic Research report produced by GlobalData Thematic Research.