| 1. |
- Oka, Kouki, et al.
(author)
-
Characterization of PEDOT-Quinone conducting redox polymers in water-in-salt electrolytes for safe and high-energy Li-ion batteries
- 2019
-
In: Electrochemistry communications. - : Elsevier. - 1388-2481 .- 1873-1902. ; 105
-
Journal article (peer-reviewed)abstract
- Li-ion batteries (LIBs) raise safety and environmental concerns, which mostly arise from their toxic and flammable electrolytes and the extraction of limited material resources by mining. Recently, water-in-salt electrolytes (WiSEs), in which a large amount of lithium salt is dissolved in water, have been proposed to allow for assembling safe and high-voltage (>3.0 V) aqueous LIBs. In addition, organic materials derived from abundant building blocks and their tunable properties could provide safe and sustainable replacements for inorganic cathode materials. In the current work, the electrochemical properties of a conducting redox polymer based on poly(3,4-ethylenedioxythiophene) (PEDOT) with hydroquinone (HQ) pendant groups have been characterized in WiSEs. The quinone redox reaction occurs within the potential region where the polymer is conducting, and fast redox conversion that involves lithium cycling during pendant group redox conversion was observed. These properties make conducting redox polymers promising candidates as cathode-active materials for safe and high-energy aqueous LIBs. An organic-based aqueous LIB, with a HQ-PEDOT as a cathode, Li4Ti5O12 (LTO) as an anode, and ca. 15 m lithium bis(trifluoromethanesulfonyl)imide water/dimethyl carbonate (DMC) as electrolyte, yielded an output voltage of 1.35 V and high rate capabilities up to 500C.
|
|
| 2. |
- Oka, Kouki, et al.
(author)
-
Conducting Redox Polymer as Organic Anode Material for Polymer-Manganese Secondary Batteries
- 2020
-
In: ChemElectroChem. - : Wiley. - 2196-0216. ; 7:15, s. 3336-3340
-
Journal article (peer-reviewed)abstract
- Manganese-based aqueous batteries have attracted significant attention due to their earth-abundant components and low environmental burden. However, state-of-the-art manganese-zinc batteries are poorly rechargeable, owing to dendrite formation on the zinc anode. Organic materials could provide a safe and sustainable replacement. In the present work, a conducting redox polymer (CRP) based on a trimer of EPE (E=3,4-ethylenedioxythiophene; P=3,4-propylenedioxythiophene) and a naphthoquinone (NQ) pendant group is used as anode in polymer-manganese secondary batteries. The polymer shows stable redox conversion around+0.05 V vs. Ag/AgCl, and fast kinetics that involves proton cycling during pendant group redox conversion. For the first time, a CRP-manganese secondary battery was fabricated with pEP(NQ)E as the anode, manganese oxide as the cathode, and manganese-containing acidic aqueous solution as the electrolyte. This battery yielded a discharge voltage of 1.0 V and a discharging capacity of 76 mAh/ganode over >50 cycles and high rate capabilities (up to 10C).
|
|
| 3. |
|
|
