Re: Budou nové Pb Aku

[Pavel Hudeček]

Pak je druhá věc jak to dopadne jako celek:
Půlka článku má 3x větší hustotu energie než celej Li, ale zatím se neví 
jak s tím zamíchá ta druhá půlka, takže to klidně může bejt větší a dražší.

PH

Dne 29.08.2024 v 12:58 konference na vojtek.biz napsal(a):
> Pokud si ještě správně pamatuji z let dávných.
> Při správné konstelaci by ten jodid / jodičnan mohl mít poměrně ostrou exotermickou reakci.
> J.V.
>
> -----Original Message-----
> From: Hw-list <hw-list-bounces na list.hw.cz> On Behalf Of Jaroslav Lukeš
> Sent: Wednesday, August 28, 2024 9:54 PM
> To: HW-news <Hw-list na list.hw.cz>
> Subject: Budou nové Pb Aku
>
> Aqueous batteries, such as the lead–acid and vanadium-redox-flow types, display restricted volumetric energy densities (less than 100 watt-hours per litre)1,2, lagging far behind non-aqueous lithium-ion batteries (300–400 watt-hours per litre)3,4. The primary reason for this inferiority is the narrow electrochemical stability window of water, which limits the operational voltage of aqueous batteries. In attempts to overcome this limitation, research has focused on important param- eters such as the charge-storing site and the number of electrons trans- ferred per redox-active material unit, for example. However, these attempts have frequently encountered problems related to sluggish electrochemical and chemical reactions, leading to recharge failures.
> Now, writing in Nature Energy, Xianfeng Li and colleagues5 at the Dalian Institute of Chemical Physics and the University of Chinese Academy of Sciences address this kinetics challenge by demonstrating a fast iodide/iodate (I−/IO3−) redox process at the positive electrode
> (catholyte) of an aqueous flow battery. The key aspect of their work is the utilization of a hetero-halogen electrolyte containing I− and Br−, facilitating multiple electron transfers as I− converts to I5+ (representing the formal charge of IO3−). This battery also benefits from a high concen- tration of redox species (6 molar I−), resulting in high energy density.
>
> These hetero-halogen systems showcase very high capacity. Cou- pling a 6 molar I− plus 1 molar Br − electrolyte with a Cd/Cd2+ anolyte, Li and colleagues showed that their cell delivers a specific capacity of around 850 ampere-hour per litre. They estimate an energy den- sity of approximately 1,200 watt-hours per litre for a half-cell with hetero-halogen species. To avoid Cd plating on the negative electrode, the team also tested silicotungstic acid or vanadium ions in the anolyte and demonstrated their potential use in aqueous batteries.
>
>   From a techno-economic perspective, Li and colleagues estimate their I−/IO3− systems to be approximately four times less expensive than
> LiFePO4 in lithium-ion batteries. However, there could be a scarcity of suitable counterpart electrolytes at the negative electrode. For exam- ple, silicotungstic acid or vanadium ions have lower solubility and lower numbers of electron transfer than I−/IO3−, necessitating high volumes of anolyte to operate the full cell. Consequently, this requirement leads to increased overall costs.
>
> https://doi.org/10.1038/s41560-024-01514-w
>
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