High energy density zinc–air microbattery utilising inorganic MCM-41 membrane

An ultrathin, high energy density zinc–air cell has been developed for potential application in microsystems. The key design feature is the utilisation of an inorganic MCM-41 membrane material with three-in-one functional elements. It serves as an insulating layer between the electrodes, as ionic exchange channels and as an electrolyte reservoir matrix. As a result, a feasible, compact cell design with high discharge capability has been demonstrated. The MCM-41 material consists of a hexagonally ordered, nanopore structure. It possesses attractive features of large surface area and pore volume, narrow pore size distribution, tunable pore size, adjustable hydrophobicity and very good thermal stability. The Zn/MCM-41/air cell measuring 1 cm2 area and ∼300 μm thick is able to deliver a maximum discharge current of 30 mA and possesses an optimum capacity of 35 mAh.