Renewable Energy Storage Solution Using Lithium Iron Phosphate (LiFePO4). LiFePO4 batteries have superior chemical and thermal stability and remain cool at room temperature. This quality makes them SAFER than other Li-ion batteries which may suffer thermal runaway and heat up faster under comparable charging conditions. Li-ion batteries have been cited as the source of several airplane accidents due to this instability. Furthermore, LiFePO4 is a nontoxic material. Many other Li-ion battery chemistries rely on cobalt dioxide (CoO2) as part of their chemistry. LiCoO2 is hazardous in nature so considered an unsafe material as it is an allergen to the eyes and skin, can cause harm when swallowed, and is dangerous and difficult to dispose of safely. Cobalt mining also releases acidic sulphides and metals such as arsenic and mercury into surrounding water systems.