Design And Performance Research On Zinc-air Battery Module For Electric Vehicle

Energy and environment pressures are driving people to seek new energy and new way of energy storage and conversion.In varieties of energy storage and conversion methods,electrochemical technology(mainly including super capacitor,metal-air battery,fuel cell,etc.)has been recognized as the most feasible and effective way to address the problem.New energy vehicles power from the power battery,as a result,the performance of the power battery directly affects the development of new energy vehicles.Recently,metal-air battery draws extensive attention for its advantages of high specific energy,low cost and environmental friendliness.Among them,zinc-air battery is recognized as the most promising one with high specific energy,rich raw materials and stable discharge voltage.At present,The research of zinc-air battery focus on developing efficient non-precious metal catalysts to promote oxygen reduction reaction in discharging process of zinc-air battery,then improve the discharging efficiency and reduce energy consumption,and reduce the cost of zinc-air battery at the same time.The performance of zinc-air battery is not only related to the catalyst,but also has close relationship with the structure of the battery,thus the battery configuration must be well designed and optimized in order to make efficient catalyst give the actual performance,Therefore,people started to research the structure of rechargeable zinc-air battery used in electric vehicle,which improves the commercialization of zinc-air battery.The research focus on designing and optimization the structure of zinc-air battery,which on the basis of homemade effective catalyst(ORR).Finally,achieving mechanical rechargeable zinc-air battery,which can meet the basic requirements of the commercialization.The main research contents are as follows:First of all,choose a good material proportion to produce the air electrode of zinc-air battery.Air electrode mainly contains a breathable waterproof layer called the gas diffusion layer,a current collector and a catalytic layer.The gas diffusion layer is made of acetylene black(70%),PVDF(30%)and PTFE(10%).The catalytic layer consists of activated carbon(60%),acetylene black(10%),PVDF(20%)and catalyst(7.9 mg)which is made up with Co-@nitrogen-doped graphene.Meanwhile the foam nickel is used as the current collector.Tested by CHI660 E electrochemical workstation,the experiment results show that the air electrode we made performs really well with good diffusion property,good cycle durabilityand long lifetime.Secondly,horizontal mechanical rechargeable zinc-air battery cell and module are designed using the air electrode we made.Then tests of the zinc-air battery assembly and constant-current charge and discharge are performed,the experiment results show that: The horizontal zinc-air monomer battery has stable discharge voltage,up to about 1.1 V;meanwhile at the current density of 5 mA/cm2、10 mA/cm2、20 mA/cm2,the specific capacity sustains at 700 mAh/g.After zinc-air monomer battery fully discharges,and zinc electrode runs out,the utilization rate could reach 100%;With constant mechanical replacement of zinc electrode,under the current density of 5 mA/cm2 for continuous charging and discharging,the zinc-air monomer battery discharge voltage is stable at around 1.1 V.For the zinc-air battery module of three monomer battery,under the current density of 20 mA/cm2 discharge,the discharge voltage basically stable at around 3.3 V,the specific capacity of zinc-air battery module can reach 239.87 mAh/g.Finally,the optimization of the horizontal mechanical rechargeable zinc-air battery is performed,aiming at designing a vertical zinc-air battery with high specific capacity.After optimization,for constant-current charge and discharge test,the experiment results show that: The vertical zinc-air monomer battery has a high open circuit voltage at about 1.4 V;Monomer battery discharge voltage is stable at about 1.2 V,higher than the horizontal zinc-air battery;under the current density of 10 mA/cm2、30 mA/cm2、50 mA/cm2 discharge,the specific capacity sustains at around 800 mAh/g,higher than the horizontal zinc-air battery by 100 mAh/g.With constant mechanical replacement of zinc electrode,under the current density of 30 mA/cm2,continuous charging and discharging,the zinc-air monomer battery discharge voltage remains stable at around 1.2 V;For the vertical zinc-air battery module of three monomer battery assembly,under the current density of 30mA/cm2 discharge,the discharge voltage stable at around 3.5 V,the discharge voltage is higher,the specific capacity of vertical zinc-air battery can reach 250.06 mAh/g,higher than horizontal mechanical rechargeable zinc-air battery,meet basic the requirements of commercialization.