Research On Fuel Cell And Battery Based On Liquid Metal Electrode

Since the 21st century,the proportion of renewable energy power generation worldwide has continued to increase,and the demand for electrochemical energy storage technology has increased.Liquid metal electrode is a key component of electrochemical energy storage equipment.On the one hand,the liquid metal electrode has the advantages of high electrical conductivity and high thermal conductivity like the solid metal electrode,on the other hand,it can effectively avoid the corrosion phenomenon and dendrite growth of the electrode.Therefore,liquid metal electrode has broad application prospects.Whether the liquid metal electrode matches the electrolyte is very important to the performance of the electrochemical energy storage device.This article will take the solid oxide fuel cell as an example to study the coupling characteristics of the liquid metal electrode and the solid electrolyte,and take the liquid metal battery as an example to study the coupling characteristics of the liquid metal electrode and the liquid electrolyte.Aiming at the corrosion problem of liquid antimony anode on the solid electrolyte in the liquid antimony anode-solid oxide fuel cell,a set of experimental system for testing the electrochemical performance of liquid metal anode-solid oxide fuel cell was built,and the button half-cell was prepared by the atmospheric plasma spraying technology.The experimental results show that the fuel cell is operating normally,and the open circuit voltage is 0.75 V,the highest power density can reach 9.7 m W/cm~2.The fuel cell performance remained stable during 4 hours of continuous operation.At the same time,it is observed that the button half-cell is tightly combined with the liquid anode,and the electrolyte is intact and not corroded by the liquid antimony.Aiming at the problem of the mismatch between the oxygen transport capacity of the liquid silver anode and the solid electrolyte in the liquid silver anode-solid oxide fuel cell,the anode material was designed and the liquid oxygen ion conductor molybdenum trioxide was introduced.Relevant electrochemical test results show that molybdenum trioxide increases the oxygen ion transport channel in the anode,improves the oxygen transport rate of the anode,and can improve the kinetic performance of the anode.When the molar ratio of molybdenum trioxide to silver is 10%,the maximum power density of the fuel cell reaches 16.82 m W/cm~2,which is 75.6%higher than the pure silver anode,while the fuel cell maintaining high stability.Aiming at the problem that the fluctuation law of the interface between the liquid metal positive electrode and the liquid electrolyte in the liquid metal battery is not clear,a two-dimensional axisymmetric dynamic characteristic research model is established based on the physical size of the 23 Ah liquid metal battery cell.The model comprehensively considers the physical processes of electrochemical reaction,magnetohydrodynamics,convection and diffusion.The flow field development inside the battery can be divided into two stages:linear growth period and saturation period.The magnetic flow in the positive electrode strengthens the mass transfer process inside the positive electrode bulk,thereby improving the electrochemical performance of the battery.The influence of battery capacity,discharge rate and electrolyte thickness on the fluctuation of liquid-liquid interface is analyzed.The larger the battery capacity,the higher the discharge rate,the thinner the electrolyte,the better the battery performance,but the more violent the liquid-liquid interface fluctuates,the more likely the battery will fail.