Aqueous zinc-organic polymer battery with a high rate performance and long lifetime

A novel redox-active polymer based on a 9,10-di(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene (exTTF) system in combination with a conjugated backbone was synthesized via rhodium (Rh)-catalyzed polymerization of 2-ethynyl(exTTF), leading to polymers with low polydispersities. Composite electrodes containing this polymer exhibited chemically reversible two-electron oxidation in aqueous media. The application of these electrodes as active cathode materials in hybrid zinc-organic batteries using an aqueous electrolyte enabled the production of air-stable charge storage systems with a theoretical capacity of 133 mAh g−1. These batteries featured high performance, charge/discharge rates of up to 120 C (30 s) and an ultra-long lifetime, of over 10 000 charge/discharge cycles (accompanied by a minor capacity loss of 14%). Finally, the polymer was compared with its nonconjugated derivative, revealing the positive influence of the conjugated backbone on the material activity owing to improved electron transfer within the polymer chain. Researchers in Germany have unlocked the secret to using water as an electrolyte in rechargeable batteries with a new conjugated polymer. Polymer batteries are flexible and lightweight, but a reliance on flammable organic solvents for electrolytes has raised concerns. Ulrich S. Schubert and colleagues synthesized a poly(acetylene)-based compound containing charge-active organosulphurs to improve battery safety while maintaining high performance. Water has a narrow range of stability under applied voltages, making it tricky to use as an electrolyte. The team's polymer, however, is capable of a reversible, two-electron oxidation reaction in this range. A prototype with the polymer cathode, a zinc anode and an aqueous electrolyte revealed the possibilities of this approach — the battery could be charged to its 1-volt potential within 30 seconds and had a lifetime exceeding 10,000 recharge cycles. The application of a conjugated polymer with 9,10-di(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene (exTTF) units as cathode and zinc as anode enables an aqueous-based hybrid organic battery. This energy storage device features ultra-high rate performance of up to a full charge in 30 s and an extended lifetime up to 10 000 cycles.