Preparation Of Silver-Fluorocarbon Composite Cathode Material And Its Application In Lithium/Sodium/Potassium Primary Batteries

Lithium/fluorinated carbon（Li/CF_x）batteries are widely used in consumer electronics,advanced medical and military defense fields due to their excellent energy density,wide operating temperature range,and long shelf life.However,the insulation of the core CF_x cathode leads to a low-rate capability that limits its application in power supplies for high-power devices.Combining CF_x with high conductivity material is an effective strategy to improve the electrode electrical conductivity and rate performance of Li/CF_x batteries.Thus,how to achieve a homogeneous and stable combination with highly non-conductor CF_x is still a tough obstacle facing the preparation of high-performance CF_x-based composite materials.Against the above background,the nano-silver particles with optimal metal electrical conductivity are uniformly and stably loaded on CF_x to effectively improves the discharge rate and voltage platform of Li/CF_x batteries by a facile and efficient electroless plating method.On one hand,the introduced fluorocarbon nanotubes with high surface energy further improve the loading efficacy and rate capability due to better wettability.On the other hand,abundantly sodium/potassium metals with low price were used as anode materials for the development of novel Na/CF_x and K/CF_xprimary batteries,which the energy density and power density are comparable to commercial Li/CF_x batteries and have promising application prospects.The specific research contents and conclusions are as follows:（1）Commercial CF_x was used as the substrate,a three-step electroless plating synthesis route of sensitization,current exchange and reduction was used to prepare silver/fluorocarbon（CF_x/Ag-x）composite materials with different silver contents by regulating the molar concentration of silver precursors.The CF_x/Ag-200 cathode prepared under 200 m M Ag NO₃ could be discharged at a maximum discharge rate of15 C（～13 A/g）in lithium primary batteries,corresponding to a power density of25616.3 W/kg,which was 100%higher than that of the commercial CF_x cathode.（2）Fluorinated carbon nanotubes（FCNTs）with abundant pore structure and excellent electronic properties were selected as substrate to further improve the loading efficacy and maximize the rate capability of Li/CF_x batteries.The prepared silver-coated FCNTs composite material（FCNTs@Ag-200）under the set of optimal plating parameters retained the original nanotubular structure and pore size distribution.The FCNTs@Ag-200 cathode with a higher specific surface area（191.808 m²/g）and activity C-F bond could be discharged at 20 C（17.3 A/g）with a specific capacity of585.94 m Ah/g,the improvement of plating uniformity also further increases the power density to 31367.35 W/kg,exceeding the prepared CF_x/Ag-200 cathode under the same conditions by 22.45%,demonstrating the well rate capability.（3）To expand the application system of CF_x cathode and reduce costs,the FCNTs@Ag-200 cathode was applied to sodium/potassium primary batteries（SPBs/PPBs）with abundant reserves.The FCNTs@Ag-200 cathode achieves a higher power density（SPBs:10 C,15852.5 W/kg）and energy density（PPBs:0.1 C,1925.2Wh/kg）according to the different standard potential and solvated radius of sodium/potassium alkali metals.Benefiting from the conductive framework formed by the loaded nanosilver particles and promoting ion diffusivity by retaining mesoporous structures,the actual performance of both primary batteries have exceeded the comparable level reported in literatures and reached a power density comparable to that of commercial Li/CF_x batteries.