The Study Of Titanium-based Positive Grid For Lead-acid Battery

It is has been 100 years since the invention of lead-acid batteries. With the continuous emergence of new battery systems and the development of technology, people have become increasingly demanding the performance of lead-acid batteries. In order to enhance the specific energy of lead-acid batteries, many researchers tend to find a new lightweight grid to replace lead.In this paper, we choose titanium plate and porous titanium as substrate for the preparation of Ti/PbO2 electrode, through galvanostatic electrodeposited method. Cyclic voltammetry and galvanostatic charge–discharge tests are performed on these electrodes to evaluate their electrochemical properties. The electrochemical performance(life) of porous Ti/PbO2 electrode is optimized by adjusting the deposition current density.In addition, we study the possibility of making the three kinds of titanium substrate materials(titanium plate, porous titanium and titanium net) as a lead-acid battery positive grid. We find that titanium net can effectively solve the problem of PAM(positive active material) shedding because of its mesh structure. It is more suitable for the preparation of pasted electrode. Therefore, we only choose titanium net as matrix to prepare Ti net/PAM electrode, and choose lead grid for comparison. Through galvanostatic charge–discharge tests to evaluate their electrochemical properties. Ti net/PAM electrode has a high initial specific capacity, but a very short life. Therefore, we conduct a preliminary exploration and research for the failure mechanism of Ti net/PAM electrode. The main achievements as follows:(1) 3D-Ti/PbO2 electrode’s specific capacity is significantly higher than the 2D-Ti/PbO2 electrodes’.(2) 3D- Ti/PbO2 has a greater electrochemical surface area because of its porous structure. A larger electrochemical surface area is the main reason of its higher specific capacity. A three-dimensional porous structure can effectively accelerate the mass transfer rate, enhance the reversibility of electrode and achieve a higher charge quantity during the charge-discharge process.(3) When prepared at different current densities, the specific capacities of these electrodes are close, but there are large differences in life.(4) Deposition current density has a great influence on surface morphology. The higher deposition current density is, the smaller PbO2 crystal particles are and the more crystal particles deposite on ‘old crystals’.(5) XRD, CV, EIS are performed on Ti net/PAM electrode(after formation and circulation failure) to investigate the associated electrochemical properties, which has proved that TiO2 is not produced during charge–discharge.(6) The results of SEM, EIS, C V, titration experiments show that the active material softening of the positive electrode lead to losing electrically connect between active material and substrate, which is the failure cause.