Preparation And Dual Performance Study Of Carbon Fiber Electrode Structure Battery

Carbon fiber composites have excellent mechanical properties such as high strength and high modulus,which are widely used in aerospace,wind power generation,and offshore vessels.In recent years,with the continuous development of carbon fiber properties,it is an interesting research topic for how to give multifunctional properties to carbon fiber while maintaining its excellent mechanical properties.Carbon fiber structure battery has both excellent mechanical properties of carbon fiber reinforced composites and better electrochemical properties of energy storage components such as lithium-ion batteries,which can store electrical energy in addition to withstanding certain loads and shocks.It has obvious advantages in achieving integrated structuralfunctional design,lightweight design and improving the overall efficiency of the system,which have attracted the attention of a wide range of researchers.Based on this,based on ultra-thin carbon fiber,carbon fiber electrodes and carbon fiber batteries that can be bent are prepared,and they are integrated into carbon fiber composites through a certain molding process to prepare structure battery tubes.The electrochemical and mechanical properties of the structure battery tubes are tested,and the structure efficiency and energy efficiency of the structure battery tubes are evaluated.Finally,the structure battery is used to supply power to the heating unit,which verifies that the structure battery can also achieve good electrochemical and mechanical properties through a certain structural design in the low temperature environment.The main research contents include the following aspects:(1)Using ultra-thin nickel-plated carbon fiber woven fabric as a collector,ultra-thin carbon fiber cathode is prepared by coating lithium iron phosphate,and paired with lithium sheet cathode to prepare buckle half-cells,which are tested for electrochemical performance and characterized for microscopic morphology.The test results show that the thinner carbon fiber unidirectional strip has lower ripple degree,which is helpful for the stress reduction of the electrode material coating;the electrode prepared by using carbon fiber as a collector fluid achieves91% of theoretical discharge capacity and 91.2% of first cycle efficiency of the electrode material;(2)The flexible bendable thin-film battery is prepared by pairing an ultrathin carbon fiber cathode with a graphite cathode and its electrochemical performance retention is testing under different bending angles.The test results show that the battery has 30% higher capacity than that of the commercial lithium iron phosphate-graphite system at the same charge/discharge multiplier;and the electrochemical performance of the battery remains basically unchanged until135° bending angle;(3)The prepared flexible bendable thin-film battery is integrated in ultrathin carbon fiber prepreg by winding method,and the structure battery tube is prepared by room temperature curing molding process,and its electrochemical performance is tested.The results show that when the bending load ratio reaches89.1N/g,the capacitance of the structure battery tube remains above 60%,and the structure battery tube can still work normally after the load is removed.The damage morphology of the structure battery tube and the full carbon fiber tube was analyzed,and the results showed that the structure battery tube may have more advantages than the full carbon fiber tube in absorbing load due to the existence of internal battery.(4)The concept of equivalent thickness is introduced,the equivalent thickness calculation formula is simulated and verified,and the structure efficiency of structure battery tube is evaluated according to the test results.The results showed that the energy efficiency and structure efficiency of the structure battery tubes were 0.61 and 0.797,respectively.(5)The prepared carbon fiber battery and heating module are integrated into the CFRP plate,and the battery supplies the heating module with energy,and its electrochemical retention performance at different temperatures is studied.The results show that due to the existence of heating module,the structure battery can maintain good electrochemical and mechanical properties under low temperature conditions.