Friday, November 29, 2024

Fast-charging lithium-sulfur battery for eVTOLs nears production

Good news! Potentially, a breakthrough!

"Researchers at Australia's Monash University are close to solving one of the biggest challenges with eVTOL aircraft. The team's new lithium-sulfur battery tech is designed to deliver roughly twice the energy density of lithium-ion (Li-ion) batteries, as well as speedy charging and discharging – enabling the sort of power delivery needed in the skies. ..."

"Monash University engineers have developed an ultra-fast charging lithium-sulfur (Li-S) battery, capable of powering long-haul EVs and commercial drones. ...

“Inspired by the chemistry of betadine, a common household antiseptic, we found a way to accelerate the charge and discharge rates, making them a viable battery option for real-world heavy-duty use,” ...

In an electric car, the Li-S batteries could power an extra 1000 kilometres on a single charge while cutting recharge time to a few hours. ...

“Our catalyst has significantly enhanced the C-rate performance of Li-S batteries, demonstrated in early proof-of-concept prototype cells. With commercial scaling and larger cell production, this technology could deliver energy densities up to 400 Wh/kg.”

“This makes it well-suited for applications requiring dynamic performance, such as aviation, where batteries must handle high C-rates during take-off and efficiently switch to low C-rates during cruising.”

Li-S batteries are also a greener alternative to the materials used in traditional Li-ion batteries, which rely on limited and often environmentally harmful resources like cobalt.” ..."

From the abstract:
"Lithium–sulfur (Li–S) batteries are considered as a viable technology offering energy-dense electrochemical energy storage systems. However, the inherently slow reaction kinetics manifested in the slow charge and discharge characteristics constrain their real-world applications. Here, it is reported that polyiodide species held within a complex polar network of polyvinylpyrrolidone (PVP) accelerate the rate-limiting solid-liquid phase transitions both in the reduction and oxidation steps during battery cycling. Density functional theory calculations support a mechanism in which a combination of enhanced binding of polysulfides and additional energy states in the PVP-iodine-polysulfide complexes accelerates the reaction pathways mediated by inter-valance polyiodide reactions within the working voltage of Li–S batteries. These studies show that PVP-iodine (PVP-I) complexes enhance the rate capability of cells with practical sulfur loadings delivering a high areal capacity of ≈7 mAh cm−2 at the practical 0.5C rate. This advantage is demonstrated in one of the highest-rate pouches reported in Li–S literature, attaining energy densities of 215 and 156 Wh kg at 0.1C and 0.3C, respectively. The results demonstrate a subtle but powerful shift in the design of molecular binder systems, which have functional roles above and beyond the role of simply holding the active materials together."

Fast-charging lithium-sulfur battery for eVTOLs nears production




Unlike Li-ion batteries, Li-S batteries use inexpensive Sulfur as a cathode material. Yes, it's cheaper - but this tech also brings drawbacks like fewer charge cycles and slow charging


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