Despite the high specific capacity and low redox potential of alkali metals, their practical application as anodes is still limited by the inherent dendrite‐growth problem. The fusible sodium–potassium (Na–K) liquid metal alloy is an alternative that detours this drawback, but the fundamental understanding of charge transport in this binary electroactive alloy anode remains elusive. Here, comprehensive characterization, accompanied with density function theory (DFT) calculations, jointly expound the Na–K anode‐based battery working mechanism. With the organic cathode sodium rhodizonate dibasic (SR) that has negligible selectivity toward cations, the charge carrier is screened by electrolytes due to the selective ionic pathways in the solid electrolyte interphase (SEI). Stable cycling for this Na–K/SR battery is achieved with capacity retention per cycle to be 99.88% as a sodium‐ion battery (SIB) and 99.70% as a potassium‐ion battery (PIB) for over 100 cycles. Benefitting from the flexibility of the liquid metal and the specially designed carbon nanofiber (CNF)/SR layer‐by‐layer cathode, a flexible dendrite‐free alkali‐ion battery is achieved with an ultrahigh areal capacity of 2.1 mAh cm−2. Computation‐guided materials selection, characterization‐supported mechanistic understanding, and self‐validating battery performance collectively promise the prospect of a high‐performance, dendrite‐free, and versatile organic‐based liquid metal battery.
This content will become publicly available on December 8, 2023
Potassium‐ion batteries (KIBs) are considered as the potential energy storage devices due to the abundant reserves and low cost of potassium. In the past decade, research on KIBs has generally focused on electrode materials. However, since electrolytes also play a key role in determining the cell performance, this review summarizes recent advances in KIB electrolytes and design strategies. Specifically, the review includes five parts. First, the organic liquid electrolyte is the most widely used type for KIBs. Its two major components, salts and solvents, have a huge impact on the formation of the solid electrolyte interphase and the performance of KIBs. Changes in salts/solvents, the introduction of additives, and the concentration increase all have a positive effect on organic liquid electrolytes. Second, the design of water‐in‐salt electrolytes can effectively widen the narrow electrochemical stability window of aqueous electrolytes. Third, despite the appealing properties, the ionic liquid electrolytes have not been widely applied due to its high cost. Fourth, the solid‐state electrolytes have drawn much attention due to high safety, and current research has been working on improving their ionic conductivity at room temperature. Lastly, perspectives are provided to support the future development of suitable electrolytes for high‐performance KIBs.more » « less
- NSF-PAR ID:
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Medium: X
- Sponsoring Org:
- National Science Foundation
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