The hybrid battery stores electrical energy and simultaneously generates useful chemicals.
Rechargeable batteries store electricity in their electrode materials, while redox flow batteries use chemicals stored in tanks attached to the electrodes. Scientists recently engineered a hybrid battery system that not only stores and provides electricity, but also generates useful chemicals in the flow system.
During use, the furfural-nickel hydroxide battery converts furfural from the biomass source into furfuryl or furoic alcohol. sour.
Furfural is a small molecule composed of pentose sugars common in agricultural biomass, and is an important chemical from which to obtain a number of feedstocks for different applications. It can be oxidized to furic acid, which is a food preservative and an intermediate in the formulation of medicines and perfumes.
When reduced, furfural turns into furfuryl alcohol, which is a precursor in resins, flavors, and medicines. Haohong Duan and a team of researchers from Tsinghua University in Beijing, China, succeeded in obtaining both value-added chemicals during the operation of the hybrid flow battery, which increases the cost efficiency of the battery system.
When charged, standard rechargeable batteries store electricity in their electrodes and feed it into the circuit as they are discharged. Another type of battery, redox flow batteries, stores electricity in chemicals, where the chemical products switch between two states and remain inside the battery. By combining the two concepts, the researchers investigated the extent to which these batteries can produce additional chemicals while storing or providing energy.
The breakthrough came in the form of a bifunctional metal catalyst for the anode. Made of rhodium and single coppercorn slugThis catalyst smoothly converted the electrolyte containing furfural into furfuryl alcohol when the battery was charged, while furfuric acid was formed when the battery was discharged. For the cathode, the researchers selected a cobalt-coated nickel hydroxide material, similar to the cathode materials used in conventional nickel-zinc or nickel-metal hydride batteries.
This combination resulted in a true dual-use battery system: after charging (using a solar cell), four series-connected hybrid batteries were able to power various devices, including LED lights and smartphones, while continuously producing furfuryl alcohol and forwick acid during the battery. cycling, where these chemicals are transported away using a flush system.
The researchers found that the new hybrid battery is comparable to a number of common batteries in terms of energy density and energy density, but delivers energy and value-added chemicals at the same time. While storing 1 kWh of energy, 0.7 kg of furfuryl alcohol is produced, and 1 kg of furic acid is produced when the system delivers 0.5 kWh of energy (on which the refrigerator can run for a few hours). However, furfural is continually fed into the system and the products must be separated from the electrolyte.
The team’s hybrid concept is a step towards improving the sustainability and cost-effectiveness of rechargeable batteries, but the concept still needs to be developed further.
Reference: “Rechargeable Biomass Battery for Storage/Generation of Electricity and Simultaneous Production of Valuable Chemicals” By Dr. Jing Li, Kaiu Ji, Puyang Li, Prof. Ming Shu, Yi Wang, Prof. Hua Zhu, Qiujin Shi, and Prof. Haohong Duan, June 6 2023, Angewandte Kimi.