Research On Technology Of The Sea-based Magnesium Air Battery

Magnesium air battery is a clean,high efficient and environment-friendly new battery developed in recent years.The battery has many advantages,for example,a good storage performance,high energy,no environmental pollution and so on.Owing to characteristic of long storage time,the magnesium air battery is especially suitable for marine emergency power.However,reaction products-Mg(OH)2 that are not rowed out in time affect the reaction rate of the magnesium air battery due to adhering to electrodes,even cause the battery irreversible expansion and destruction.The land-used magnesium air battery deigned at present can rely on artificial replacement of electrolytes,while this replacement is not realistic or impossible for the magnesium air battery used on the sea.The key to the application of a magnesium air battery to the ocean is how to make the magnesium air battery to replace the electrolyte automatically without consuming its chemical energies of a battery.First of all,in view of the above problems,this paper first presented a kind structure of magnesium air battery with the function of automatic replacement of electrolyte.In order to increase the battery voltage and capacity,this paper presented a design scheme of multi cavity series and circumferential distribution magnesium air battery.In order to realize the replacement of electrolyte,the driving unit of a pendulum was put forward.The electrolyte replacement device absorbed the kinetic energy of the waves by the eccentric pendulum and generated the torque that was pushed the ratchet to rotate after the pawl transmitting to the ratchet.The power was finally transmitted to a turntable with a special bulge after the torque was increased by the speed reducer.Then the valve can be opened when the valve at the bottom of the seawater chamber contacted with the bulge on the turntable.The valve under the action of the external force can be opened and the valve under the action of its restoring spring also can be closed after external force was removed.The valve avoided generating internal consumptions among chambers.The battery included 6 magnesium alloy anodes and 12 air cathodes.There were 6 air chambers and 6 seawater chambers in the battery cavity.The battery cover plate has air inlets and hydrogen outlets located in the corresponding places of seawater chambers and air chambers.A magnesium alloy anode and a valve for controlling the delivery of the electrolyte were arranged in each seawater chamber.This paper finished the manufacturing and assembling of a battery prototype.Secondly,this paper analyzed the hydrodynamic performance of the floating body of the magnesium air battery by AQWA software.The frequency analytical results showed the RAO value was the large when the wave angle was 90°,and the maximum value of RAO in roll and pitch were obtained when the wave frequency was 0.79 Hz.Time analytical results showed when the wave height was below 0.9m,the roll angle of the battery was not more than 30°and the pitch angle was not more than 32°.The analytical results showed that work of the battery floating body was basically safe when the effective wave height was below 0.9m.Finally,this paper tested the performance of the device and the battery.The test of the device used for replacing electrolyte showed the effect of the pendulum was better when the roll angle was 25°.The pendulum quality test showed the quality of the pendulum should be selected among reasonable value when the device was designed.Battery performance test showed the battery open circuit voltage maintained at 8±0.5V.Marine test showed that the prototype has basically met design requirements.