Ionic Liquid-assisted Cathode Catalytic Material For Lithium Thionyl Chloride Battery

Lithium thionyl chloride batteries?Li-SOCl₂?have received extensive attention due to their high energy density.However,the safety and stability of batteries,voltage hysteresis,and catalytic activity of cathode catalysts are still the key factors that restrict the performance of Li-SOCl₂ batteries.At present,commonly used cathode catalysts are transition metal?Co,Ni,V,Cu,Mn?complexes of phthalocyanine and porphyrin,binuclear metal phthalocyanine complexes,soluble transition metal macrocyclic compound catalysts,carbon electrode materials,etc.However,as a new type of functionalized material,ionic liquids have been well used in energy-related fields because it can be used not only as a precursor for the preparation of Li-SOCl₂ battery electrode catalysts,but also as a regulator of carbon materials.Based on these studies,two kinds of ionic liquids and carbon materials composite catalysts were prepared using ionic liquids as precursors and used as cathode catalysts for Li-SOCl₂ batteries.Meanwhile,when the ionic liquid is used as a regulator,a carbon material having a high active site is prepared by compounding with a carbon material of biomass.The main contents and conclusions are as follows:?1?Non-precious N-doped carbon nanotube catalyst materials with remarkable electrocatalytic properties were prepared by dehydration condensation of carboxylated carbon nanotubes with functionalized ionic liquid guanidine carbonate?[G]₂[CO₃]?in low temperature hydrothermal carbonization.The N-CNTs catalyst was then added to the carbon cathode of the Li-SOCl₂ battery.The discharge test of Li-SOCl₂ battery showed that the discharge capacity of Li-SOCl₂battery increased significantly to 3543 mAh g^-1 when the N-CNTs catalyst with a mass fraction of 5%was doped in KB carbon,and the operating voltage of the battery was also increased by 0.12 V.?2?The functionalized ionic liquid[VMIm][DCA]was uniformly mixed with the nano-copper oxide,and then a certain amount of AIBN was added.After heating in a constant temperature water bath for 80 h under a nitrogen atmosphere,a poly?ionic liquid?encapsulated CuO was obtained.The prepared PIL@CuO was calcined at 550^oC in a tubular furnace under a nitrogen atmosphere,and the CuO wrapped in PIL was reduced to Cu nanoparticles by the C formed during the reaction.Finally,a mesoporous composite catalytic material of N-C@Cu was formed and used as a cathode catalytic material for the Li-SOCl₂ battery.?3?The sponge-like substance in the pomelo skin was mixed with an ILs,and then calcined?550°C?under a nitrogen atmosphere to form a g-C₃N₄ structure which wrapped around the carbonized grapefruit skin.In order to adjust the content of the N element,different mass fractions of IL are added before calcination.At the same time,the precursor was immersed in the solution containing KOH for a period of time,and then sintered under a nitrogen atmosphere?900°C?,finally a three-dimensional porous nitrogen-doped composite of g-C₃N₄ covered carbonized grapefruit skin was obtained and used as carbon material for Li-SOCl₂ batteries.The results show that the performance of the carbon cathode of the structure is much higher than that of commercial acetylene black.