Lithium News

The notorious polysulfide shuttle severely impedes the practical application of Li-S batteries. Utilizing various electrocatalysts to improve the polysulfide redox kinetics has emerged as a promising strategy to address the shuttle effect.

The electronic structure of the electrocatalysts plays a decisive role in determining the catalytic activity to facilitate the polysulfide conversion. Therefore, reasonably modulating the electronic structure of electrocatalysts is of paramount significance for improving the electrochemical performance of Li-S batteries. However, previous reviews focus on the classification of catalytic materials in term of their physical and chemical properties, which ignores the relationship between electronic structure and catalytic activity.

Recently, a research team led by Profs. Liang Zhang and Yanguang Li from Soochow University in China systematically summarized the strategies for optimizing the electronic structure of electrocatalysts for Li-S batteries and established the relationship between electronic structure and catalytic activity. Future perspectives and challenges are also proposed for designing high-efficient electrocatalysts to construct high-energy-density and long-lifetime Li-S batteries. The review was published in Chinese Journal of Catalysis.

A comprehensive overview of the fascinating strategies to tailor the electronic structure of electrocatalysts for Li-S batteries is presented, including vacancy engineering, heteroatom doping, single atom doping, band regulation, alloying, and heterostructure engineering.

Vacancy engineering aims at creating more active sites and tune the surface charge-transfer property. Meanwhile, vacancies can significantly promote the electrocatalytic activity by optimizing the surface-adsorption ability for reaction intermediates, which derives from the abundance of localized electrons around vacancies. Additionally, the vacancies can tailor the surface hydrophilic property for a better electrolyte contact.

In summary, designing sulfur host materials with high catalytic activity has provided a new direction towards high-performance Li-S batteries. The high-efficiency electrocatalysts with high activity and special functions can be obtained through the coordination of various electronic structure regulation strategies, which can further improve the electrochemical performance of Li-S batteries and also enlighten other energy-related processes based on multi-electron reactions.

Solid-state batteries (SSBs) are currently regarded as a promising battery technology of the future. Compared to the current lithium-ion batteries, which are used in mobile phones, laptops and electric vehicles, SSBs could achieve even higher energy densities and better safety. In addition to research institutes, all major automotive companies are therefore also researching this technology.

The main feature of the technology is that the highly flammable liquid electrolytes of lithium-ion batteries are replaced by a solid. The entire battery is therefore consists of only “solid materials,” hence the name solid-state battery. In order to produce such a battery, different materials (anode, cathode and electrolyte) must be pressed together under high pressure.

Researchers from the Helmholtz-Zentrum Berlin and Hereon, Humboldt-Universität zu Berlin and the Federal Institute for Materials Research and Testing have now succeeded in observing the processes within such a solid-state battery during charging and discharging. The team led by Prof. Philipp Adelhelm and Dr. Ingo Manke investigated the behavior of copper sulfide, a naturally occurring mineral, as a cathode in a solid-state battery. Lithium was used as anode. A special feature of the battery is that large copper crystallites form during discharge.

The formation of large crystallites enables a detailed investigation of the reaction by means of X-ray tomography. Thus, the (dis)charge reaction could be traced in 3D and for the first time the movement of the cathode particles within the battery could be tracked. In addition, it was shown that cracking can be effectively reduced by higher pressure.

“For the complex measurements, we had to make some compromises and carry out many reference experiments,” explains Dr. Zhenggang Zhang and Dr. Kang Dong, the joint first authors of the publication. “However, the results provide detailed insights into the inner workings of a solid-state battery and show how its properties can be improved.”

Hyundai Motor Group announced in October that will it build in Georgia a large manufacturing site, called Hyundai Motor Group Metaplant America (HMGMA), which is expected to include also an EV battery manufacturing facility.

The partner for the battery joint venture has not been announced yet, but according to an unofficial report from The Korea Economic Daily Global Edition, Hyundai is in talks with SK Innovation’s SK On. Another candidate interested in the deal reportedly is LG Energy Solution.

Two South Korean companies joining forces would not surprise us, especially because they are already working together on various projects. SK On also already has two battery plants in Commerce, Georgia (9.8 and 11.7 GWh per year) and clearly is in an expansion mode.

According to the article, undisclosed sources indicate that on the table is an investment of 2.5 trillion won ($1.9 billion), which would potentially result in a battery gigafactory with an output of roughly 20 GWh/year (pouch cells, nickel-rich NCM chemistry).

A memorandum of understanding between Hyundai and SK On might be announced later this month (on November 28), according to the report.

20 GWh per year for a plant, which is expected to produce 300,000 electric cars annually, would mean 67 kWh per car on average. We consider it kind of low (especially if the plant would be used for larger EVs, like SUVs), but maybe it’s an initial target.

The output would have to be higher also if SK On would like to supply batteries for other Hyundai Motor Groups plants in the US (another one in Georgia and one in Alabama).

Anyway, it’s an interesting rumor that indicates ongoing preparations by South Korean companies to improve their market position in the US, by the way of the general transition to electric cars.

Let’s wait those few days to see whether an official announcement will confirm the battery partner for the Hyundai Motor Group Metaplant America plant in Georgia.

We just reported on a rumor floating around in the Chinese press that BYD will begin manufacturing sodium-ion batteries in the first half of 2023, a rumor that the company has denied. Yet today the company announced it will build a new battery factory in Wenzhou, China, that will produce 20 GWh of batteries by the time it is finished in 2024.

But what kind of batteries will it make? That is the key question and BYD is being coy about answering it, other than to say in a press release that the batteries made in the new factory will be “produced with one of the currently available promising battery technologies.”

BYD is heavily involved with its Blade batteries, which use LFP chemistry. But is it possible the new factory will be the first to manufacture sodium-ion batteries? Of course, anything is possible. However, the timing of the rumor and the new announcement certainly suggest that’s what BYD is planning. There are also rumors that BYD may be close to manufacturing solid-state batteries. If true, that would make it the first company in the world to do so.

CnEVPost reports that BYD currently has about 20 power battery production bases in China, and is one of the largest battery manufacturers in China, second only to CATL. Globally, it ranks third in battery production behind only CATL and LG Energy Solution. In China, BYD is far and away the largest manufacturers of vehicles with plugs, many of them buses that use the company’s LFP battery chemistry.

In August, BYD signed a strategic cooperation agreement with the Yichun city government in Jiangxi province, where it plans to invest $4 billion in a power battery factory as well as a mining project. The factory will have an annual capacity of 30 GWh while the mining project will be able to produce 100,000 tons of battery grade lithium carbonate and ceramic clay, including lithium, annually.

The Takeaway

The comments to our prior story are far more informative than anything in the press reports and rumors coming out of China. If you want to know more about the pros and cons of sodium-ion batteries, scoot on over to the comments section of that post. As always, I am amazed at the breadth and depth of knowledge CleanTechnica readers have at their fingertips. I often learn as much from our them as I do from the internet.

Chinese inverter manufacturer and storage system provider Zhejiang Beny Electric Co., Ltd. has unveiled a 2.5 kWh battery for residential applications.

“Our new residential solar energy storage battery pack can be flexibly scaled up to 10 kWh,” a spokesperson from the company told pv magazine. “It can be combined with BENY PV components, microinverters, and EV chargers to form a complete solar energy, battery storage and EV charging solution.”

The modular device measures 450 mm x 400 mm x 200 mm and has a weight of 32 kg. When stacked in a four-device configuration its size reaches 700 mm x 400 mm x 200 mm and the weight increases to 104 kg.

The battery has a storage capacity of 2.5 kWh and a nominal voltage of 48 V. Its operating voltage ranges from 44.8 V to 57.6 V.

The lithium-ion system uses LiFePO4 as the cathode material and has an ambient operating temperature range of -20 C to 60 C. It also features an IP54 protection level, convecting cooling, and can purportedly operate for more than 5,000 cycles.

“The modular design of the battery pack is easy to transport, and the wiring is simple and easy to install,” the spokesperson went on to say.

Based in Wenzhou, China, Beny Electric recently launched a micro-inverter series for residential and commercial PV systems.