Cr^(3+)和Ni^(2+)复合掺杂的尖晶石氧化物用于提高钻孔热电池放电性能（英文）

Cr^(3+) and Ni^(2+) Co-doped Spinel Oxide Cathode with Improved Capacity and Voltage Stability in Thermal Battery for Geothermal Borehole

为了提高用于油气以及地热钻井热电池正极材料的比容量和电压稳定性,将Cr和Ni离子同时掺杂到尖晶石锰酸锂中。通过固相法制备的LiCr_xNi_yMn_(2-x-y)O_4(0≤x≤0.3,0≤y≤0.3)材料显示出结晶度良好的尖晶石相结构和规则的八面体形态。研究了LiCr_xNi_yMn_(2-x-y)O_4材料与LiNO_3-KNO_3共晶电解质的热相容性以及LiCr_xNi_yMn_(2-x-y)O_4/Li-Mg-B电池体系在10～30 mA·cm^(-2)的电流密度以及200～300℃的温度范围内的放电性能。用Cr^(3+)和Ni^(2+)部分取代尖晶石中的锰,增强了尖晶石结构的稳定性,从而提高电池的电压和容量。其中,LiCr_(0.1)Ni_(0.3)Mn_(1.6)O_4在10 m A·cm^(-2)和300℃的条件下具有最大比容量713.29 mAh·g^(-1),在LiNO_3-KNO_3熔盐电池中放电性能良好。

In order to enhance specific capacity and voltage stability of cathode material for thermal battery used in oil/gas and geothermal boreholes, Cr and Ni ions were doped into spinel lithium manganate simultaneously. The LiCrxNiyMn2-x-yO4 (0≤x≤0.3, 0≤y≤0.3) material prepared by solid-state method showed a good purity of spinel phase and a regular octahedral crystalline particles morphology. We investigated the thermal compatibility of the LiCrxNiyMn2-x-yO4 material with LiNO3-KNO3 eutectic electrolyte and the discharge performance of LiCrxNiyMn2-x-yO4/Li-Mg-B battery system at current densities from 10 to 30 mA·cm^-2 over a temperature range of 200 to 300 ℃. Partial substitution of Cr^3+ and Ni^2+ for Mn in spinel improved battery voltage and capacity due to the enhanced stability of spinel structure, and the LiCr0.1Ni0.3Mn1.6O4 had the maximal specific capacity of 713.29 mAh·g^-1 at 10 mA·cm^-2 at 300 ℃, showing great potential in LiNO3-KNO3 molten salt battery for geothermal borehole applications.