These special conditions do not apply to changes in pre-certified non-rechargeable lithium battery installations, when the only change is aesthetic or to relocate the installation to improve the safety of the aircraft and occupants. For this reason, many laptop manufacturers protect their batteries with a secret code that can only be accessed by the corresponding computer. A team of scientists was concerned that batteries were still too toxic to power medical devices found inside the human body. We evaluate these risks with the help of existing literature on the thermal and safety modeling of lithium-ion batteries in the context of an aerial environment, together with mitigation strategies for them.
To find a viable compromise between high energy density, operational safety and good current supply, lithium-ion battery manufacturers can mix metals. Non-rechargeable lithium batteries are novel and unusual with respect to the state of technology considered when these requirements were codified. One of the main risk factors for batteries used in aviation is the possibility of thermal leaks when temperatures reach the flash point of one of the components of the cell and, finally, they cascade onto several cells, causing the failure of the battery pack throughout the system and a risk of fire. Designing safely around the dendrite problem is a fundamental design consideration for lithium metal batteries.
The temperature would rise rapidly to the melting point of metallic lithium and cause a violent reaction. However, the FAA has found that the presence of non-rechargeable lithium batteries in certification projects is not always immediately identifiable, as the battery itself may not be the focus of the project. In the case of flyable batteries, cell ventilation must take into account the possibility of a low-pressure environment in an aircraft. The FAA anticipates that non-rechargeable lithium batteries will be installed in most aircraft makes and models in the transportation category.
The FAA believes that the safety benefits of upgrading to a 406 MHz ELT for operations in Alaska will outweigh the risk of battery fire. Therefore, the answer to the question of whether altitude affects batteries directly on Earth is yes, but not as directly as one might have thought. The most common degradation mechanisms mentioned in the literature are the formation of the solid electrolytic interface (SEI), the isolation and loss of active material (LAM) due to mechanical stress and particle cracking, and the lithium coating.