Study On Flexible Micro Direct Menthanol Fuel Cell Array

Micro Direct Methanol Fuel Cell(μDMFC)is a device that directly converts chemical energy into electrical energy by consuming methanol and oxygen to carry out an oxidation-reduction reaction.It has the advantages of low environmental pollution,simple system structure,and high energy density.Compared with other types of batteries,it is more suitable as portable energy source for mobile devices such as mobile phones and wearable electronic devices.However,the open circuit voltage of a single μDMFC is generally 0.5-0.7 V,which cannot meet the power requirements of electrical equipment.At the same time,traditional μDMFCs are mostly made of silicon or other hard materials,which are difficult to meet the needs of flexible electronic devices and wearable products.In this regard,this paper proposes a flexible micro direct methanol fuel cell array,which is of great significance to the application of portable wearable energy devices.Aiming at the problem that the voltage of single μDMFC cannot meet the requirements of most electrical equipment and the rigid structure of traditional μDMFC is not suitable for wearable electronic products,this paper designs a flexible μDMFCs.First,a flexible printed circuit board is used as the substrate of the cell array,on which the fuel cell array and six connection modes are designed.Then,according to the layout on the flexible printed circuit board,a membrane electrode assembly with a diameter of 3.5 mm was prepared.The cathode and anode plates are prepared by sputtering Au metal with a thickness of 200 nm on the surface of stainless steel to achieve the purpose of reducing surface resistance and enhancing corrosion resistance.Next,in order to reduce the size of the μDMFC and make the μDMFC more integrated and portable,a two-piece buckle replaced the traditional way of fixing the cell with screws in the cell design,and the unit cell is clamped by the buckle.In addition,polydimethylsiloxane is used to prepare flexible end plates for battery packaging.Finally,the cell is assembled to form a flexible μDMFCs array.Experiments were carried out on the flexible μDMFCs.First,the performance of the single cells in the array under different methanol concentrations was investigated.Secondly,under the passive liquid feeding method,the influence of six electrical connection methods on the performance of the flexible μDMFCs was explored.Then the influence of methanol concentration on the performance of the μDMFCs is studied,and the voltage response characteristics of the μDMFCs are evaluated through the square wave load current of different cycles.Then the performance of the μDMFCs under different bending degrees was investigated,and the stability of the μDMFCs was tested and analyzed.Finally,under the active liquid supply mode,the influence of different concentration and different flow rate operating parameters on the performance of flexible μDMFCs was studied.The experimental results show that the optimal methanol concentration for single cell and passive flexibleμDMFCs is 4 mol/L.In the test of different electrical connection methods,different connection methods do not affect the power of μDMFCs,and the output voltage value can be changed for different loads,which is suitable for different electrical equipment and improves the practicability of the μDMFCs.It has a voltage response under different cycles of square wave loads,and a greater degree of bending is conducive to the improvement of μDMFCs performance.The active flexibleμDMFCs achieves the best performance at a methanol concentration of 3 mol/L and a flow rate of 0.6 m L/min.