High specific energy flexible CuO thin film cathode for thermal batteries

Abstract

Through the simple tape-casting and doctor blade methods, the flexible CuO thin film cathode with great mechanical strength for thermal battery is fabricated. The cathode still can be effectively discharged after being bent 500 times at degree of 150°. The single cells are assembled and discharged at 480 °C by using Li–B alloy as anodes. The specific energy reaches 836.4 W h kg−1 at the current density of 200 mA cm−2 with the cut-off voltage of 1.7 V. It is strikingly improved in comparison to the conventional cold-pressed cathode. The reason underlying may be that the flexible CuO thin film cathode possesses higher density and utilization, and the lower average pulse resistance of the battery (0.234 Ω) makes the large current discharge achieved. The successful fabrication of the flexible thin film cathode lays the foundation for the development and application of full-component flexible thermal battery even flexible lithium ion battery.