Research On Performance Of Cathode And Anode Materials For Dissolved Oxygen Seawater Battery

The dissolved-oxygen seawater battery is widely used in the field of ocean exploration because of its good environmental adaptability and discharge stability.It is mainly composed of a magnesium alloy anode and a dissolved-oxygen cathode.Magnesium alloy is an excellent electrode material,but it has the problem of selfcorrosion and low utilization when applied to seawater batteries.The discharge performance of the dissolved-oxygen cathode is highly susceptible to environmental factors.Starting from these two problems,this paper conducts stannate conversion treatment and silanization treatment on magnesium alloy anodes in order to improve the corrosion resistance of the alloy and improve the utilization rate.The physical properties of the two alloy layers on the magnesium alloy anode are studied.The influence of electrochemical performance;at the same time,the composition of the dissolved-oxygen cathode and the factors affecting the discharge of the battery were investigated.A light gray stannate conversion film was successfully prepared on the surface of magnesium alloy by impregnation method.The microscopic morphology of the film layer is a micron-sized spherical particle packing structure,which can effectively isolate the contact between the substrate and the corrosive medium and thus inhibit corrosion.The optimum process conditions for the conversion of stannate were obtained by single factor experiment and orthogonal test on the composition of the solution and the process parameters.The research shows that the corrosion resistance of the magnesium alloy after the conversion treatment is much larger than that of the bare magnesium alloy.The constant current discharge test was carried out on the seawater battery composed of magnesium alloy and cathode material.The results show that the specific capacity of the magnesium alloy anode after conversion treatment is 1621.68 m Ah/g,which is 36% higher than that of the bare magnesium alloy 1190.1 m Ah/g.Electrode utilization increased by 15%.The stannate film on the surface of the magnesium alloy was subjected to silanization treatment,and a stannic acid-silane composite film layer was obtained on the surface of the magnesium alloy negative electrode.The corrosion resistance and hydrophobic properties of the treated magnesium alloy were improved,the specific discharge capacity of the battery was increased to 1714.3 m Ah/g,and the electrode utilization rate was 75%.The effects of different conductive agents and catalysts on the physical properties of the cathode materials and the discharge performance of the battery were also investigated.The PVDF solution is more suitable as an electrode binder,while the conductive agent is a Super P material.The influence of other parameters in the discharge process of the battery was studied.When the positive and negative pole spacing was 8 mm,the discharge performance of the battery was the best.As the discharge current density increased,the discharge voltage of the battery gradually decreased,so the dissolved oxygen seawater battery was more Suitable for long-term power supply with small current.In this paper,the market economy analysis of the preparation of the surface layer of magnesium alloy anode is carried out.It is found that the cost of stannate conversion,silanization treatment and preparation of dissolved-oxygen cathode on the surface of magnesium alloy were relatively low,and the process was simple and large-scale use.The feasibility and market prospects are broad.