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toitoimontoi
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This website is depressing. Previous news, published 2 days ago : http://www.greencarcongress.com/2015/10/20151026-gr%C3%B6ger.html (open-acess review) "On the Li-sulfur side, it is difficult to achieve the expected gravimetric energy density from a lithium sulfur battery-system. Along with that, the requirements of the automotive industry have also changed over the years, with increased focus on volumetric energy density rather than only gravimetric energy density. The achievable volumetric energy densities for lithium—sulfur batteries, independent of the anode, will always be substantially lower than that of lithium ion batteries, the authors observe" And then a news like that is published, only describing a nice scientific work, and people in the comment section are already talking about commercialization, 5-5-5 goals... You really think that this paper does change something ? Use of silicium, sulfur, graphene, the worst materials for volumetric densities, change anything in terms of energy densities ? Warping silicium in polymer increases energy densities ? And it is like that all the time. It will be the same for the next Si-graphene-ionic-liquid-nano-sulfur-whatever-battery, with excellent cycle life obviously. When are you going to understand that scientific work is only scientific ? They don't even use relevant metrics (mAh/g ?) for pratical applications. (Don't get me wrong, this is a really good work in terms of material science.)
Also, there are way too many scientific publications. Some blogs take their generic sentences, like "to the point that the battery is now considered to be near to industrial production", way too seriously. Metrics used in scientific publications are often not even relevent for industrial applications... mAh/g ? amazing, but in your lab you avec so few mg/battery that there are no links to real application.
The article cited here is a review, which means that they did not do anything but reviewed the previous work made by others. I don't see any report claimed in this article in the sources. Problems with all the Si and sulfur based batteries is 1/ cyclability in full cell (i.e. not vs. lithium) and 2/ volumetric energy density (expansion more than 200%, porous electrode needed...). If you do Si-Li-S battery, you have both of them. I will just cite the article cited here : "However, regardless of the way of introduction of lithium ions into the system, the reported full-cells – Li–Si/S–C72b and Si/Li2S–C73a – showed relatively low specific capacities (e.g., a first discharge capacity of 423 mA gLi2S at a specific current of 389 mA g1 ) as well as a constant and rather rapid capacity fading after 20 cycles." If you talk with project managers in auto industry (nissan, bmw, vw), they don't expect to use sulfur as batteries because at the moment you don't gain any energy density compared to optimized Li-ion systems. Newt generation batteries will be all-solid-state (for safety, and maybe the use of lithium metal) and silicium-Ni/Mn-rich batteries, which will be benefit from the work made on current Li-ion.
Interesting paper. No data about thermal stability (critical issue for nano) and volumetric density (how do you make thicker electrodes ?), so I guess you guys can continue talking about commercialization for a long long time...
Should work with LFP, but it does not increase cycle life (see Fig5 in the paper). Problems with nanosized structures are their long-term stability, and their thermal stability (never discussed in any paper).
LiNO3 has been used for like forever in lithium-sulfur batteries for its well-known passivation of lithium metal, and these guys just do a nature coms on it today... As if it was a big news. (and magnesium metal does not form dendrites...)
Regarding battery research, a lot is funded by private companies such as car manufacturers or chemical producer. I have never been more free to do research than when I was funded by a private company actually, so it is not that easy. I still believe that comparison with moore's law, a-bomb or other technologies are very misleading. One has to look at into details to anticipate what will be the leading technology in the battery market. Oversimplifying is not always that good.
These comparisons made very often here and there are very misleading. First because there is no point of comparison between making a battery and putting a guy on the moon (some challenges that could appear way "easier", because less fancy ?, than getting on the moon have been unsolved for decades). But also because, industrial work is not comparable with very specialized work. Put one man on the moon, at any cost, is something. Develop an industrially viable device - especially for mass production - is something totally different.
@Sublime voltage (around 1.5-3.5V) and energy densities are pretty low, but the article is a proof of concept. I don't think they aim any commercialization of the system.
I agree with the last comment, I have seen many Eos presentations and they only show results from a small prototype. 160¤/kWh is only based on assumptions. Generally, estimations of battery costs are very very difficult to analyse. In the case of li-ion batteries, research have totally under-estimated the capabilities of market-leading manufacturers (Nissan, Tesla...) to reduce costs, as shown in this recent paper (sorry if you don't have access) : http://www.nature.com/nclimate/journal/v5/n4/full/nclimate2564.html As it has been said above, major breakthroughs at the pack level are today coming from process. It cannot be easily taken into consideration since manufacturers do not communicate about it.
It's 44Wh/kg in the article. They are comparing to all-solid LCO/LTO. "The respective first discharge capacities of the SE-NW-SE and pNW-SE-pNW LCO/LTO cells, 85 and 89 mA h gLCO–1, translate to energy density values of 42 and 44 Wh kgcell–1. Figure 4e shows the cell energy density of all-solid-state cells as a function of the overall weight fraction of SE. The energy density obtained in this work (44 Wh kgcell–1) is still much lower than that (100–200 Wh kgcell–1) of commercialized LIBs(52) and also some conventional ASLB adopting high-capacity electrode materials such as sulfur (e.g., ∼150 Wh kgcell–1 assuming that Li metal can be used.). It should be noted, however, that by applying the bendable and thin NW-SE film, the energy density of the LCO/LTO ASLB was almost three times higher than that of the conventional ASLB (15 Wh kgcell–1) that does not contain NW. "
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May 3, 2015