Qing, TingtingMilitary and planetary application requires high energy density rechargeable battery with an extremely wide operating temperature range. Current rechargeable batteries only operate in a narrow range from -20 ℃ to 60 ℃. Low ionic conductivity of electrolyte and sluggish lithium ion diffusion of electrode at a low temperature, the irreversible phase transition at elevated temperature limit broadening operating temperature range of battery. In this research, a novel zinc battery LiFePO4/Li2ZnCl4.9H2O/Zn with wide operating temperature range between -70 ℃ and 70 ℃ has been developed. The Li2ZnCl4.9H2O electrolyte has very high ionic conductivity at -70 ℃, while the PEDOT coating on LiFePO4 reduce the side reaction at 70 ℃. At 70 ℃, LiFePO4@PEDOT/Li2ZnCl4.9H2O/Zn cells provide a capacity of 130 mAh.g-1 achieved over 20 cycles at 0.3 C, with a high rate capability. It also showed a stable cycling at -70 ℃ with 133 mAh.g-1 for 50 cycles at 0.1 C.enThesisChemical engineering