Polyaniline and water pre-intercalated V2O5 cathodes for high-performance planar zinc-ion micro-batteries

The imperative development of high-performance planar micro-batteries featuring high-capacity electrodes and environmentally safer, cost-effective systems is crucial for powering forthcoming smart, miniaturized portable electronic devices. In alignment with this necessity, this study centers on achieving high-capacity cathode materials. This involves the pre-intercalation of polyaniline and water into V2O5 nanowires to enhance capacity, applied in conjunction with Zn anodes within a planar device structure to boost charge storage performance. The presented straightforward strategy is demonstrated to not only effectively increase charge storage capacities from 235 mAh/g to 384 mAh/g at 200 mA/g but also reduce the pre-activation process. Consequently, the Zn-ion micro-batteries obtained, featuring high-capacity cathodes, not only provide a substantial areal capacity of 409 μAh/cm2 but also exhibit notable peak areal energy density and power density at 306.7 μWh/cm2 and 3.44 mW/cm2, respectively. Additionally, the micro-battery demonstrates a slow self-discharge voltage response, with approximately 80 % retention even after 200 h. This work proposes an effective strategy to enhance the electrochemical performance of planar micro-batteries, a critical advancement for the development of advanced portable electronics.