Preparation And Performance Study Of Sodium Ion Battery Based On NTP@Gr Negative Electrode

Sodium-ion battery has received extensive attention because of its rich resources,balanced distribution,low cost,and similar electrochemical mechanism to lithium ion battery.It is a new generation of energy storage battery with great potential.In view of the current problems of poor electronic conductivity,large volume change,unstable power supply voltage and poor electrochemical performance of electrode materials for sodium ion batteries,this paper proposes to carry out high specific capacity,small volume change rate,and stable single-value voltage Research on the platform’s Na Ti₂（PO₄）₃（NTP）electrode materials,using microwave-assisted FB（fluidized bed）-PECVD（plasma enhanced chemical vapor deposition）method to coat NTP with high-quality graphene to reduce irreversible capacity and improve Its electronic conductivity opens up a new research idea and solution for the improvement of the performance of sodium ion battery anode materials.The main contents of the full text study are as follows:（1）Solvent-heat assisted sol-gel method was used to prepare NTP nanomaterials.By controlling the reaction temperature and time,small-size（approximately 100 nm）,monodispersed NTP nanoparticles were obtained.The electrode preparation and battery assembly process were optimized.When the active material loading was 2.56 mg/cm² and the active material:PVDF:acetylene black component mass ratio was 8:1:1,NTP showed the best electrochemical performance.After heat treatment,the NTP precursor has a high degree of crystallinity and exhibits good electrochemical performance.It has a reversible specific capacity of about 105 m Ahg^-1 at a charge and discharge current density of 0.5 C,and it still has a high current density of 10 C.Can work normally.（2）The NTP@rGO composite electrode material was prepared by the thermal solvent method and heat treatment.Its microscopic morphology shows a composite structure in which highly crystalline NTP nanoparticles are nested on the sheet graphene oxide.Using sodium metal as the counter electrode,the specific capacity of the first cycle of the NTP@rGO composite material can reach 120m Ahg^-1 at a charging and discharging current density of 0.5 C.At a current density of 5 C,there is still 68 m Ahg^-1 Reversible specific capacity,its electrochemical performance has been significantly improved compared to the original NTP material.（3）Innovatively use FB-PECVD method to grow graphene on the surface of nano-NTP particles,control the flow rate of CH₄ and H₂ to 20 sscm and 5 sccm,respectively,and grow at 800 W microwave power for 45 min to obtain NTP@Gr nanocomposite material.The material exhibits high charge-discharge specific capacity and excellent long-cycle stability in organic electrolyte.The specific capacities at charge and discharge rates of 0.5 C,2 C,5 C,10 C,and 20 C are 130,108,101,98 and 69 m Ahg^-1.The specific discharge capacity after 1000 charge-discharge cycles at 10 C current rate is about 82 m Ahg^-1,and the retention rate is 81%.This method can effectively solve the problems of uneven rGO coating and poor quality in the solvent gel method.