Cr3+ and F− co-doped lithium manganese oxide cathode for medium-temperature reserve primary cell

Medium-temperature molten salt reserve primary cell utilizes low-melting nitrate electrolyte, that is considered suitable for geothermal borehole as well as oil and gas exploration . In this work, Cr 3+ and F − ions were introduced into spinel lithium manganate oxides by high-temperature solid-state method and verified by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The effects of fluorine content on the morphology and discharge performance of the LiCr 0.1 Mn 1.9 O 4− x F x (0 ≤  x  ≤ 0.5) have been studied in LiCr 0.1 Mn 1.9 O 4− x F x /LiNO 3 -KNO 3 -Ca(NO 3 ) 2 /Li-Mg-B system. Fluoride-doped samples have a significant improvement in discharge performance at the condition of 10 mA·cm −2 and 250 °C because of the stabilization of the crystal structure. Factors of operating temperature and current density have a significant effect on battery discharge performance, and the surroundings of 10 mA·cm −2 and 200–250 °C contributes the battery to achieve high performance. That indicates the LiCr 0.1 Mn 1.9 O 4− x F x /LiNO 3 -KNO 3 -Ca(NO 3 ) 2 /Li-Mg-B battery shows great potential in geothermal borehole as well as oil and gas exploration environment.