Performance and Degradation of A Lithium-Bromine Rechargeable Fuel Cell Using Highly Concentrated Catholytes

Abstract

Lithium-air batteries have been considered as ultimate solutions for the power source of long-range electrified transportation, but state-of-the-art prototypes still suffer from short cycle life, low efficiency and poor power output. Here, a lithium-bromine rechargeable fuel cell using highly concentrated bromine catholytes is demonstrated with comparable specific energy, improved power density, and higher efficiency. The cell is similar in structure to a hybridelectrolyte Li-air battery, where a lithium metal anode in nonaqueous electrolyte is separated from aqueous bromine catholytes by a lithium-ion conducting ceramic plate. The cell with a flat graphite electrode can discharge at a peak power density around 9mW cm -2 and in principle could provide a specific energy of 791.8 Wh kg -1 , superior to most existing cathode materials and catholytes. It can also run in regenerative mode to recover the lithium metal anode and free bromine with 80-90% voltage efficiency, without any catalysts. Degradation of the solid electrolyte and the evaporation of bromine during deep charging are challenges that should be addressed in improved designs to fully exploit the high specific energy of liquid bromine. The proposed system offers a potential power source for long-range electric vehicles, beyond current Li-ion batteries yet close to envisioned Li-air batteries.

Flexible Solid Flow Electrodes for High-Energy Scalable Energy Storage

“…This configuration decouples the power and energy and enables new materials combinations for scalable FBs. We discuss three examples of applying SFE configuration to enable fully scalable high-energy-density and low-cost flow battery systems: (1) Scalable anode to replace Li metal in hybrid Li-redox FBs, including Li-polysulfide, 28 Li-halides, 26,27 Li-organic radicals 15 etc. Li metal on anode reduces scalability of the FBs and causes safety concerns.…”

Two‐Electron Redox Chemistry Enabled High‐Performance Iodide‐Ion Conversion Battery

“…The inherent liquid properties and severe corrosiveness exclude Br 2 from a portable configuration and only permit a flow one. [9] Conventional LiÀ I batteries have always been restrained by the controversial I À /I 3 À or I À /I 2 redox reactions, accompanied by an output plateau below 2.9 V and a limited theoretical capacity of 211 mAh g I À 1 . [8a] Nonetheless, the positive I + cation is thermodynamically unstable in the electrolytes and hardly progresses the reversible conversion.…”

Silicon–Carbon Nanocomposite Semi-Solid Negolyte and Its Application in Redox Flow Batteries

“…), organic active materials (TEMPO, MeO–TEMPO, ferrocene-based liquid, etc.) and high-solubility aqueous posolytes (LiI, LiBr, , etc.) were investigated as the posolyte.…”