| 1. |
- Park, Jimin, et al.
(författare)
-
A Dual-Functional Electrolyte Additive for High-Performance Potassium Metal Batteries
- 2023
-
Ingår i: Advanced Functional Materials. - 1616-3028 .- 1616-301X. ; 33:48
-
Tidskriftsartikel (refereegranskat)abstract
- Potassium metal batteries (KMBs) coupled with layered transition metal oxides as cathode materials are a promising energy−storage technology owing to low cost and high capacity. However, uncontrollable dendritic growth in the K−metal anode and chemical reactivity of the layered transition metal oxide cathode against the electrolyte solution cause KMBs to suffer from low Coulombic efficiency, rapid capacity fading, and critical safety issues. In this study, an electrolyte engineering strategy is introduced by introducing adiponitrile (ADN) as a dual−functional electrolyte additive containing an electron−rich nitrile group (C≡N) in its molecule structure. Thus, the addition of 1 wt.% ADN can alter the chemical properties of the electrolyte solution, thereby improving the anode−electrolyte and cathode−electrolyte interfacial stabilities in KMBs. The formation of a potassiophilic compound with C≡N in the solid electrolyte interphase layer can guide the uniform electrodeposition of K and suppress the dendritic growth in the K−metal. Moreover, C≡N forms a strong coordination bond with the oxidized transition metal, leading the reversible redox reactions by mitigating the undesirable disproportionation reaction and improving the thermal stability of the layered transition metal oxide cathode. Computational calculations and experimental characterizations are used to verify the role of ADN additive in enhancing the electrochemical properties of KMBs.
|
|
| 2. |
- Park, Jimin, et al.
(författare)
-
Stable Solid Electrolyte Interphase for Long-Life Potassium Metal Batteries
- 2022
-
Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 7:1, s. 401-409
-
Tidskriftsartikel (refereegranskat)abstract
- Potassium (K) is considered to be the most suitable anode material for rechargeable K batteries because of its high theoretical capacity (686 mAh g(-1)) and low redox potential (-2.93 V vs SHE). However, uneven electrodeposition of K during cycling usually leads to the growth of dendrites, resulting in low Coulombic efficiency and compromising battery safety. Herein, we develop a strategy for stabilizing K metal through simple interface control. The conductive passivation layer can be controllably designed by a spontaneous chemical reaction when a K metal foil is kept in contact with a liquid-phase potassium-polysulfide (PPS); this guides the formation of an electronically and ionically conductive solid electrolyte interphase layer including K2S compound, enabling dense K plating with a dendrite-free morphology. Compared to the bare K metal anode, the PPS-treated K metal anode demonstrates superior cycling stability in symmetric half cells and full cells using a TiS2 cathode under practical constraints.
|
|
