In-situ investigation of the water absorption/desorption behavior of LiFePO4

► LiFePO4 is a promising positive electrode material for large-scale Li-ion batteries. ► Recent studies however indicate stability issues under humid conditions. ► Controlled-humidity thermobalance can be used to in-situ monitor water absorption. ► Both the extent and the speed of water absorption depend on the humidity level. ► Additives used in composite electrode protect the material against water absorption.