SAFETY OF RELiON® LITHIUM IRON PHOSPHATE (LiFePO4) BATTERIES
I. Introduction The news media, internet and battery marketplace is filled with misinformation regarding the safety of lithium batteries. RELiON has always placed safety as the highest priority in all their lithium battery products. This document has been created by RELiON to assist customers, distributors, OEMs and the engineering community to better understand the differences in lithium battery technologies.
II. Lithium Chemistries There are three main lithium chemistries. Lithium Cobalt LiCoO2 Lithium Nickel-Manganese Cobalt Oxide (NMC) LiNiMnCoO2 Lithium Iron Phosphate LiFePO4 (LPF) Source: Battery University As shown in the diagrams above LiFePO4 is the safest lithium chemistry. III. Why do Lithium Ion batteries explode or catch fire? The main cause of fire or explosion of a lithium ion battery is excessive overheating during charging, which causes a perpetuating reaction called thermal runaway.
IV. Chemical and Thermal Stability of Lithium Iron Phosphate (LiFePO4) The LiFePO4 technology that is built into every RELiON battery possesses superior chemical and thermal stability over other lithium chemistries, which means better battery safety. LiFePO4 is an intrinsically safer cathode material than cobalt oxide or manganese oxide cathode. Technically speaking, the fully “lithiated” and “unlithiated” states of LiFePO4 are physically similar, which means it’s structurally stable.
VI. Battery Management System Provides Extra Protection RELiON’s batteries are all equipped with an internal or external BMS which protect against the following potentially damaging circumstances: 1. Over-Voltage 2. Under-Voltage 3. Over-Current 4. Over Temperature 5. Short Circuit 6. Cell Imbalance The BMS will disconnect the battery from the circuit if any of these events occur. VII. Safety Test Protocols RELiON’s cells are UL1642 certified and have been tested per IEC62133 standards.
