Improving Electrochemical Performance in Planar On-Chip Zn-ion Micro-Batteries via Interlayer Strategies

The imperative development of planar on-chip micro-batteries featuring high-capacity electrodes and environmentally safer, cost-effective, and stable systems is crucial for powering forthcoming miniaturized systems-on-chip smart devices. However, research in the area of high-stability micro-batteries is limited due to the complex fabrication process, the stability of micro-electrodes during cycling, and the challenge of maintaining higher capacity within a limited device footprint. In response to this need, this study focuses on providing highly stable and high-capacity micro-electrodes. This involves adding a PEDOT layer between the electrode material and the current collector, applied within a planar polyaniline cathode and zinc anode device structure to enhance charge storage performance. This straightforward strategy not only improves device stability over long-term cycling and reduces charge transfer resistance but also increases charge storage capacities from 17.64 to 19.75 µAh cm^{- 2} at 0.1 mA cm^{- 2}. Consequently, the Zn-ion micro-batteries achieve notable peak areal energy and power of 18.82 µWh cm^{- 2} and 4.37 mW cm^{- 2}, respectively. 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.