The article “How an accidental discovery made this year could change the world.”, written by Lockett (2022), introduces the discovery of using Lithium-sulfur (Li-S) as a new variation for rechargeable batteries and its benefits. Li-S batteries could be the catalyst in the advancement of batteries. It boasts possibilities of cheaper manufacturing costs, three-fold lighter batteries and finally, a reduction in involuntary battery combustions. However, Li-S batteries typically have a charge cycle of around 1000 charges, half that of Li-I batteries. Thus, in my opinion it is necessary to improve its charge cycles.
However, According to Li. et al., (2015, P. 1), although promising, researchers had difficulties increasing the charge cycle of the Li-S batteries. “Unfortunately, uncontrolled dendritic and mossy lithium growth, as well as electrolyte decomposition inherent in lithium metal-based batteries, cause safety issues and low Coulombic efficiency.” The dissolving of lithium polysulfides into the electrolyte, which lowers battery efficiency, results in the "shuttling" effect. Although Pai. et al., (2022, P. 1) mentioned that researchers found a chemical phase of sulfur that prevented batteries’ degradation: “Here, we stabilize a rare monoclinic γ-sulfur phase within carbon nanofibers that enables successful operation of Lithium-Sulfur (Li-S) batteries in carbonate electrolyte for 4000 cycles.” The authors implied that the reaction that creates polysulfides could be nullified with the introduction of gamma sulfurs. Pai. et al., (2022, P. 4) also stated that the deterioration rate of the new Li-S batteries was minimal even after 4000 cycles: “The carbonate-based battery exhibits high reversible capacity, which stabilizes to 800 mAh·g−1 in the first few cycles and then it remains stable with a small 0.0375% decay rate over 4000 cycles. The cells exhibit a high capacity of 650 mAh·g−1 even after the end of 4000 cycles.”
According to Lockett, Li-S batteries have the potential to bring about a significant transformation in society. Personally, I strongly believe that Li-S batteries should replace Li-I batteries. This is because Li-S batteries are not only cheaper and lighter in weight, but they also have a lower ecological impact. Moreover, since sulfur is abundantly available on Earth, Li-S batteries offer a more sustainable solution. However, it is important to note that the widespread use of Li-I batteries may make it challenging for Li-S batteries to gain widespread adoption immediately. Nonetheless, with time, I am confident that Li-S batteries will overtake Li-I batteries as the preferred energy storage option.
Rechargeable batteries and the parts that make up the batteries' ecological cost are a growing concern. Li-I batteries usually contain nickel and cobalt, as was previously mentioned. These minerals are produced through significant mining activities, with cobalt mining being the primary cause for worry (Gifford, 2020). When cobalt is exhausted from mine sites, miners extract the cobalt from private property, agriculture, and residences which pollutes the food and water near these areas. Additionally, cobalt and other metal mining by-products have the potential to harm soil, water, and air. (Northwestern University, 2021). On the other hand, sulfur is abundant, so much so that the US Geographical Survey classifies it as nearly limitless and produced on several continents. Additionally, according to environmental regulators, sulfur does not pose any significant health dangers (Gifford, 2020).
The use of sulfur in lithium batteries would be a better choice when compared to Li-I batteries due to the abundance of sulfur, therefore impacting its cost. Li-S substitutes cobalt, which is sensitive to weak global supply networks for sulfur, a cheap raw element that is a by-product of the oil industry. Additionally, Li-S prices per unit of power can result in considerable savings. (Merrifield,2020). Lithium cobalt oxide (LCO), lithium nickel cobalt manganese oxide (NMC), and lithium nickel cobalt aluminum oxide (NCA) are the three Li-I battery types considered in this comparison. Sulfur is 550 times less expensive than cobalt and 243 times less expensive than nickel. (Benveniste et al., 2018). According to research on drones, Li-S, which costs about €72 per kWh and is 30% cheaper than comparable Li-I technology, may result in significant cost savings (Merrifield, 2020).
Li-S batteries' superior energy density per unit weight over Li-ion batteries is also a key selling point (Gifford, 2020). The energy density of the present Li-S ranges from 200 to 500 Wh/kg, while that of the LCO, NMC, and NCA is 240 Wh/kg, 220 Wh/kg, and 260 Wh/kg, respectively (Benveniste et al., 2018). High energy density batteries have longer run times compared to smaller batteries. They can generate the same amount of energy while having a reduced environmental impact than batteries with lower energy densities. (Cloud, 2020). As a result, Li-S batteries can be more compact, lighter, and longer-lasting between charges.
One issue with Li-S batteries is that although they have a theoretical maximum energy density of 2600 Wh/kg, they have only been able to produce 500 W/kg, which is one of the problems researchers are trying to overcome. High sulfur loading and high sulfur utilization are necessary to produce higher energy densities. Despite the researchers' talks and creation of some parameters, it hasn't been possible to meet all these standards at once (Feng et al.,2020).
In summary, Li-S batteries offer a compelling alternative to Li-I batteries due to their lower cost, lighter weight, and reduced ecological impact. However, while the electric vehicle market continues to expand, Li-S batteries have not yet achieved commercial viability. Currently, researchers are working to increase energy density and overcome degradation issues to make Li-S batteries more efficient. If successful, Li-S batteries could soon replace Li-I batteries and become the preferred energy storage option. Therefore, it is essential to continue investing in research and development to enhance the performance of Li-S batteries and accelerate their adoption in various applications.
References
Benveniste, G., Rallo, H., Canals Casals, L., Merino, A., & Amante García, B. (2018). Comparison of the state of lithium-sulfur and lithium-ion batteries applied to electromobility.
https://upcommons.upc.edu/bitstream/handle/2117/121911/comparison_state.pdf;sequence=1
Cloud, M.(2020, August 21). What is the energy density of a lithium-ion battery? Flux power. https://www.fluxpower.com/blog/what-is-the-energy-density-of-a-lithium-ion-battery
Feng, Y., Wang, G., Ju, J., Zhao, Y., Kang, W., Deng, N., & Cheng, B. (2020, November). Towards high energy density Li-S batteries with high sulfur loading: From key issues to advanced strategies. Energy Storage Materials, 32, 320-355.
https://www.sciencedirect.com/science/article/pii/S2405829720302658?fr=RR-2&ref=pdf_download&rr=7522a044ab458829
Gifford, S.(2020, July). Lithium-sulfur batteries: advantages. The Faraday Institution.
https://www.faraday.ac.uk/lis-advantages/
Lockett, W. (2022 ,April 17). How an accidental discovery made this year could change the world. BigThink.
https://bigthink.com/the-future/lithium-sulfur-batteries/?utm_medium=Social&utm_source=Facebook&fs=e&s=cl&fbclid=IwAR1JQ-VrPK4Nt6YauDpwVZrmkeHE1jR0zfHdUdqe1wC5xr4XEabacCNVJLE#Echobox=1658939001-1
Li, W., Yao, H., Yan, K., Zheng, G., Liang, Z., Chiang, Y., & Cui, Y. (2015, June 17). The synergetic effect of lithium polysulfide and lithium nitrate to prevent lithium dendrite growth. Nature Communications, 6. https://www.nature.com/articles/ncomms8436
Merrifield R. (2020, June 05). Cheaper, lighter and more energy-dense: the promise of lithium sulfur batteries. European Commission.
https://ec.europa.eu/research-and-innovation/en/horizon-magazine/cheaper-lighter-and-more-energy-dense-promise-lithium-sulphur-batteries#:~:text=Rather%20than%20using%20costly%20cobalt,power%20can%20offer%20substantial%20savings
Northwestern University. (2021, December 17). Understanding cobalt’s human cost:Social consequences of green energy must be assessed in addition to environmental impacts, researchers say. ScienceDaily.
https://www.sciencedaily.com/releases/2021/12/211217113232.htm#:~:text=Waste%20generated%20from%20mining%20cobalt,were%20unsafe%2C%20unfair%20and%20stressful
Rahul Pai, R., Singh, A., Tang, M., & Kalra, V. (2022, February 10). Stabilization of gamma sulfur at room temperature to enable the use of carbonate electrolyte in Li-s batteries. Nature Communications.
https://www.nature.com/articles/s42004-022-00626-2?utm_medium=affiliate&utm_source=commission_junction&utm_campaign=CONR_PF018_ECOM_GL_PHSS_ALWYS_PRODUCT&utm_content=textlink&utm_term=PID100062364&CJEVENT=70ab9fddb82a11ec811f534d0a18050f
Thanks, Yeow Min, for the revision.
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