When choosing a deep cycle battery for your motorhome or caravan in New Zealand, you may have come across the option of a LiFePO4, or lithium iron phosphate, battery. But what makes LiFePO4 batteries different from other lithium-ion batteries, and how do they compare in terms of safety?
One key factor to consider is the risk of thermal runaway. This process can occur in lithium-ion batteries when they are overcharged or subjected to physical damage. During thermal runaway, the battery overheats and may catch fire. This can be a serious hazard, especially in confined spaces like a motorhome or caravan.
How are LiFePO4 safer than other lithium batteries?
Phosphate-based batteries, like lithium iron phosphate batteries, offer a superior chemical and mechanical structure that does not overheat to unsafe levels. This increases safety compared to lithium-ion batteries made with different cathode materials.
The charged and uncharged chemical states of LiFePO4 are physically similar and highly robust, which allows the ions to remain very stable during the oxygen flux that occurs during charge cycles or possible malfunctions. The iron phosphate-oxide bond is stronger than the cobalt-oxide bond found in other lithium chemistries, so when the battery is overcharged or subjected to physical damage, the phosphate-oxide bond remains structurally stable and does not release excessive heat. This means lithium iron phosphate batteries are not prone to thermal runaway.
In addition to their increased safety, LiFePO4 batteries have other advantages over lithium-ion batteries. They are incombustable, meaning they will not burn when exposed to fire. This is an important feature in the event of mishandling during charging or discharging. Lithium iron phosphate batteries can also withstand harsh conditions, including freezing cold and scorching heat, as well as rough terrain. This makes them a reliable choice for use in recreational vehicles.
