Aqueous OH-/H+ Dual-ion Gradient Energy Assisted Electrochemical Energy Storage and Conversion Devices

Abstract

The majority of energy research is going on in harvesting renewable energy resources due to the global warming and pollution associated with fossil fuel based energy sources. However, renewable energy resources exhibit temporal and geographic fluctuations which demand electrochemical energy storage and conversion devices to bridge the gap between the peak of energy availability and the peak of energy demand.1-3 However, the performance of electrochemical energy devices are often limited by their threshold energy storage capability, voltage window, parasitic chemistry, electricity ineffective electrolysis etc. We show how the performance metrics of state of the art energy storage and conversion devices can be remarkably targeted by harvesting the hidden electromotive force available with OH-/H+ dual-ion gradient. This hidden electromotive force available with OH-/H+ dual-ion gradient is utilized to expand the voltage window in aqueous supercapacitors from 1.23 V to 2 V by arresting the parasitic water splitting reaction. This eventually leads to boosting the energy density of supercapacitors without compromising their power capability.4 The hidden electromotive force available with OH-/H+ dual-ion gradient can be exploited in a water electrolyzer for simultaneous water splitting and desalination of saline water in an electricity effective pathway.5 Using semiconductor electrodes, the hidden electromotive force available with OH-/H+ dual-ion gradient can be further utilized for substantially lowering the external bias required in a conventional photo electrochemical water splitting device. Finally, OH-/H+ dual-ion gradient energy can be efficiently tapped which reduce the overpotential of counter reactions to make electro-organic synthesis more efficient and cost effective and electricity effective electro organic synthesis paired with hydrogen fuel synthesis.6 1. Ding Y.; Cai P.; Wen Z.; Electrochemical neutralization energy: from concept to devices: Chem.Soc. Rev., 2021, 50, 1495. 2. Zhong, C., Liu, B., Ding, J. et al. Decoupling electrolytes towards stable and high-energy rechargeable aqueous zinc–manganese dioxide batteries. Nat Energy 2020, 5, 440–449. 3. Cai P.; Chen K.; Lu Z.; Mondal R.; Musthafa O.T.; Wen Z. Aqueous OH-/H+ Dual-Ion Zn-Based Batteries. ChemSusChem 2022, e202201034 ,1-16 4. Sur S.; Kottaichamy A. R.; Bhat Z. M.; Devendrachari M. C.; Thimmappa R.; Musthafa O.T.; A pH dependent high voltage aqueous supercapacitor with dual electrolytes. Chem Phys Letts 2018, 712,160-164. 5. Sur S.; Thimmappa R.; Bhat Z. M.; Dargily N.C.; Mukhopadhyay S.; Liu X.; Cai P.; Wen Z.; Musthafa O.T.; Hybrid Alkali–Salt–Acid Electrochemical Device for Electricity-Efficient Desalination and H2 Generation. ACS Sustain. Chem. Eng. 2022, 10, 10781–10788. 6. Sur S.; Mondal R.; Thimmappa R.; Mukhopadhyay S.; Musthafa O.T. ; Aqueous OH-/H+ Dual-ion Gradient Assisted Electricity Effective Electro-Organic Synthesis of 2,5-Furandicarboxylic Acid Paired with Hydrogen Fuel Generation. J. Colloid Interface Sci. (ASAP)