Sustainable Continuous Scale Synthesis of Positive Material for High-performance Wearable Aqueous Zn Metal Batteries

One factor limiting the development of wearable, aqueous zinc metal batteries has been the inability to continuously synthesize high-performance positive electrodes quickly, efficiently, and sustainably. In this work, a continuous and scalable synthesis of high-performance positive electrodes at room temperature by situ electrochemical synthesis and activation of MOF materials on flexible current collectors was developed. The process avoids the time-consuming, material-consuming, energy-intensive, and hazardous 'one pot' solvothermal method commonly used, and yields flexible positive electrodes (Ni_0.7Co_0.3(HBTC)(4,4'-bipy) based double hydroxide on flexible substrates) with good performance. After matching with a negative electrode made out of zinc, the energy densities of the whole wearable devices reach ∼319 Wh L^-1 for fiber batteries and ∼264 Wh L^-1 for planar batteries, respectively. This advancement can provide an effective method to narrow the gap between lab and industrial production and promote the practical application of wearable aqueous zinc metal batteries.