Redox‐Active Functional Electrolyte for High‐Performance Seawater Batteries

Abstract

DedicatedtoProfessor Reshef Tenne on the occasion of his 75th birthdayRechargeable seawater batteries have gained recognition as key sustainable electrochemical systems by employing the near-infinite and eco-friendly catholyte seawater.H owever, their practical applications have been limited owing to the low chemicala nd electrochemical stabilityo ft he anode component. Herein, as tability-secured approach was developed by using sodium-biphenyl-dimethoxyethane solution as ar edoxactive functional anolytef or high-performances eawater batteries. This anolyte system shows high electrochemical stability, superior cycle performance, and cost-effectiveness over conventional electrolyte systems. Figure 2. Voltage profiles of Na-BP-DME upondesodiation/sodiation processes in (a) Na-BP-DME electrode j Na metal cell and (b) SWB full cell at 0.5 mA cm À2 . Figure 4. Cycle performance of as eawater coin cellwith (a) Na-BP-DMEa nd (b) NaTf-TEGDME at acurrent density of 1mAcm À1 .Insitu DEMSd ata of (c) SUS mesh/Na-BP-DME/seawater and (d) SUS mesh/NaTf-TEGDME/seawater DEMSc ell. (e) 1 HNMR (400 MHz, CDCl 3 )s pectra of desodiated BP-DME.

Dual‐Use of Seawater Batteries for Energy Storage and Water Desalination

“…Apart from avoiding side reactions leading to cell swelling and failure, the anode material must combine good conductivity, a suitable electrochemical stability window at a low voltage range, and low cost and toxicity. [52] Elemental sodium is highly abundant and frequently used as an electrode material, with a very high theoretical capacity of 1166 mAh g −1 . [43,[53][54][55][56] However, uncontrolled growth of sodium dendrites hinders safe battery operation, ruptures separators, and shortens the device lifetime while still exhibiting low Coulombic efficiency and battery performance.…”

Development of Prismatic Cells for Rechargeable Seawater Batteries

“…[8] The research on anode active materials that play a role as the storage of sodium ions from seawater has been in-depth conducted. [9][10][11][12] In addition, steady progress of the current collector with electrocatalysts has been simultaneously investigated to reduce overpotentials generated in oxygen evolution reaction and oxygen reduction reaction (OER/ORR) at the cathode. [13][14][15] Beyond materials, challenges remained regarding the need and significance of cell design development to reach theoretical energy densities (Figure 1a,b).…”

“…The charging and discharging voltage profiles were measured with a saturated sodium (Na)-biphenyl (BP) in dimethoxyethane (DME) as anolyte materials, which enabled to realize the prismatic cell design owing to a redox-active functionality. [10,11] The discrete type was used as the cathode current collector. A discharge capacity and energy density at a constant current of 0.59 mA cm -2 were obtained by 8.5Ah and 23 Wh (242 Wh L -1 ), respectively (Figure 4a).…”

Seawater Battery-Based Wireless Marine Buoy System With Battery Degradation Prediction and Multiple Power Optimization Capabilities

“…However, even if the amount of charge increases, only the amount of Na metal increases and the state of the material does not change [18]. Since it is driven in infinite seawater, the cell voltage is not affected [19]. Consequently, the SWB cells shows that the open circuit voltage (OCV) finally regress to constant cell voltage after its charge or discharge operations are done [20].…”