Comparison of thermal stability between micro- and nano-sized materials for lithium-ion batteries

• The thermal stability is critically dependent on its oxidation/reduction activity.
• The difference in thermal stability is small for LTO with different particle size.
• No big difference is seen in thermal stability of LFP with different particle size.
• The nano-sized LCO exhibits less thermal stability than the micro-sized LCO.

The thermal stabilities of several electrode materials of Li-ion batteries (Li4Ti5O12, LiFePO4, and LiCoO2) with different particle size (micro and nano-scale) under lithiated or delithiated state have been investigated using differential scanning calorimetry. The thermal stability (exothermic peak temperature and heat flow) is critically dependent on its oxidation/reduction activity. Both lithiated Li4Ti5O12 and delithiated LiFePO4 show slight differences in thermal stability between the nano- and micro-scale, while delithiated nano-sized LiCoO2 exhibits lower exothermic peak temperature and larger thermal runaway than the micro-sized LiCoO2.