5 ms·

Alright domain experts of HN - tell me why this is too good to be true.

by qeternity 5y ago

jokoon 5y ago
At this point any submission related to battery tech research should be removed.
- rsfern 5y ago
  Why? I haven’t seen a silver bullet yet, but I always learn something new
  - grishka 5y ago
    I think GP's point is that Li-Ion batteries were state of the art 15 years ago, and they still are today. And they aren't much better either, they still degrade from normal use and still expand if you look at them wrong. Except 15 years ago they at least were designed to be easily replaceable.
    - Retric 5y ago
      This is a Li-Ion battery because Lithium isn’t one single technology it’s a family of batteries that use Lithium. So lithium titanate, lithium cobalt, lithium manganese oxide, nickel cobalt manganese(NCM), nickel cobalt manganese Aluminum(NCMA), lithium iron phosphate(LFP), and now lithium sulfer are all related but they have very different trade offs. 15 years ago Li-Ion battery tech meant worse trade offs so fewer charge cycles, slower charging, less energy per charge, more costly etc etc. And yes, NCM and NCMA both use lithium.
    - 41b696ef1113 5y ago
      Li-ion has made tremendous advances in that time. This article[0] goes through some of the history. Some hot takes: - Price per cell has dropped ~97% since 1991 - 1991 energy density ~200 Wh/liter; 2005 energy density ~500 Wh/liter; 2017 ~700 Wh/liter [0]: https://pubs.rsc.org/en/content/articlelanding/2021/ee/d0ee02681f https://pubs.rsc.org/en/content/articlelanding/2021/ee/d0ee0...
    - Tagbert 5y ago
      As Xoa posted in another branch, it’s not true that batteries aren’t much better in the last 15 years. Lithium Ion is not a single type of battery but a category of batteries with many types, each with their own benefits and challenges. Numerous changes have been made to the anode and cathodes to improve stability, power capacity, recharge cycles and cost. Recent efforts have focuses on reducing or removing cobalt. Capacity has grown about 5% per year and general stability has improved. I remember reading articles like this years ago where they talked about using LFP cathodes to improve the stability of batteries. Today LFP batteries are used in some Teslas and probably other vehicles. https://arstechnica.com/science/2021/05/eternally-five-years-away-no-batteries-are-improving-under-your-nose/ https://arstechnica.com/science/2021/05/eternally-five-years...
- gameswithgo 5y ago
  The cynicism for battery teach research is misplaced. In our lifetimes we have seen real enormous strides in battery technology actually go into production. LFP batteries are now in actual Teslas, provider a cheaper/safer/simpler option for lower range cars that depend on fewer exotic materials/mining. Sodium batteries are in the pipeline. Sulfur batteries may or may not make it too.
- lordnacho 5y ago
  The nature of science is disappointment, no? Maybe this will work... Nope. Maybe this other way? Nope. Now and again there's an actual advance and we rejoice, but if you keep an eye on cutting edge stuff it's got to happen a lot that some promising lead leads nowhere.
  - rzzzt 5y ago
    Reporting could be delayed until the advance happens. Even better if I can buy it in a store at that point.
    - Fordec 5y ago
      I'll take "How we end up with scientists running around in circles making the same mistakes over and over." for $500. If you goal is to learn about things once they're stable and working, I suggest drop reading science journalism from your schedule and just start window shopping at electronics stores.
      - rzzzt 5y ago
        OK, I was thinking more of summaries of summaries of university news portal announcements on tech sites (which this one is not). I am not against academic publications, scientists should definitely be acquainted with what is happening in their field.
- scythe 5y ago
  >Electrochemical characterization and post-mortem spectroscopy/ microscopy studies on cycled cells reveal an altered redox mechanism that reversibly converts monoclinic sulfur to Li2 S without the formation of intermediate polysulfides for the entire range of 4000 cycles. The development of unconfined high loading sulfur cathodes in Li–S batteries employing carbonate- based electrolytes can revolutionize the field of high energy density practical batteries. [italics mine] These are bold claims. You don't hear that every day. Polysulfides have been an accepted fact of life in Li-S batteries forever.
perlgeek 5y ago
I haven't read the whole thing yet, and I'm not really a battery expert, but a battery needs to check really many boxes to be viable in a commercial product. Among these are: ability to mass produce, resistance to mechanical stresses, safety, peak performance, low auto-discharge, ability to recycle, energy density, charge cycles, efficiency, availability of materials, operational temperature range, storage temperature range. The latter criteria seem to be well addressed in the paper, the first few not really, or only tangentially (based on a quick ctrl+f for some of the key words).
- deleted 5y ago
  [deleted]
scythe 5y ago
They successfully used an electrolyte that has been refusing to work for the last 20 years of research on the topic. That's pretty good. Carbonate (ester) electrolytes are unparalleled in stability. But the abstract says that they're made using sulfur stabilized by[1] carbon nanofibers[1]. Great: now make a million of them. 1: EDIT: nanofibers stabilize the sulfur, but it is not encapsulated. The phrasing "within" in the abstract threw me for a loop.
- formvoltron 5y ago
  Engineering seems easier to improve than science.
  - upofadown 5y ago
    It does? Most things fail in implementation.
- photochemsyn 5y ago
  Here's the step-by-step production they used, it doesn't seem implausible that this could be scaled up in a factory setting. Maybe a modular approach would work, i.e. you might have 100 production lines running simultaneously, each one running the following ~8 steps: Material synthesis Synthesis of CNFs. The free-standing CNFs were made by electrospinning. Typically, 10 wt% polyacrylonitrile, was added to DMF and stirred overnight to form a polymeric solution. This solution was then loaded into a Becton Dickinson 5 mL syringe with a Luer lock tip and an 18-gauge stainless steel needle (Hamilton Corporation). The syringe with the needle was connected to a NE-400 model syringe pump (New Era Pump Systems, Inc.) to control the feeding rate of the solution. The grounded aluminum collector was placed 6 in. from the tip of the needle. Electrospinning was performed at room temperature with a relative humidity below 15%. A potential difference of 7–8 KV (Series ES -30 KV, Gamma High Voltage Research, Inc.) was applied between the collector and the tip of the needle. The flow rate of the solution was kept constant at 0.2 mL h−1. The as-spun nanofibers were collected and stabilized in a convection oven at 280 °C for 6 h in air atmosphere. The stabilized nanofiber mats were then placed in alumina plates and carbonized in a nitrogen environment up till 900 °C at a ramp rate of 2.5 °C min−1 and then activated under CO2 flow for 1 h in a horizontal tube furnace (MTI. Corp). The furnace was then cooled at 2 °C min−1 until it reached room temperature. Monoclinic γ-sulfur deposition on CNFs. The free-standing CNF mats were pun- ched with stainless steel die (φ = 11 mm) and dried at 150 °C overnight under vacuum. The CNF discs were then weighed and placed in an in-house developed autoclave (Stainless steel 316) and subjected to 180 °C for 24 h in an oven. The autoclave consisted of a sulfur reservoir at the bottom and a perforated disk for placing electrodes at the top. After 24 h the autoclave was cooled to room tem- perature slowly in a span of 6–8 h. The electrodes were weighed and transferred in an Argon-filled glove box via overnight room temperature vacuum drying in the antechamber for battery fabrication.
known 5y ago
deleted 5y ago
[deleted]

Alright domain experts of HN - tell me why this is too good to be true.

jokoon 5y ago

At this point any submission related to battery tech research should be removed.

rsfern 5y ago
Why? I haven’t seen a silver bullet yet, but I always learn something new
- grishka 5y ago
  I think GP's point is that Li-Ion batteries were state of the art 15 years ago, and they still are today. And they aren't much better either, they still degrade from normal use and still expand if you look at them wrong. Except 15 years ago they at least were designed to be easily replaceable.
  - Retric 5y ago
    This is a Li-Ion battery because Lithium isn’t one single technology it’s a family of batteries that use Lithium. So lithium titanate, lithium cobalt, lithium manganese oxide, nickel cobalt manganese(NCM), nickel cobalt manganese Aluminum(NCMA), lithium iron phosphate(LFP), and now lithium sulfer are all related but they have very different trade offs. 15 years ago Li-Ion battery tech meant worse trade offs so fewer charge cycles, slower charging, less energy per charge, more costly etc etc. And yes, NCM and NCMA both use lithium.
  - 41b696ef1113 5y ago
    Li-ion has made tremendous advances in that time. This article[0] goes through some of the history. Some hot takes: - Price per cell has dropped ~97% since 1991 - 1991 energy density ~200 Wh/liter; 2005 energy density ~500 Wh/liter; 2017 ~700 Wh/liter [0]: https://pubs.rsc.org/en/content/articlelanding/2021/ee/d0ee02681f https://pubs.rsc.org/en/content/articlelanding/2021/ee/d0ee0...
  - Tagbert 5y ago
    As Xoa posted in another branch, it’s not true that batteries aren’t much better in the last 15 years. Lithium Ion is not a single type of battery but a category of batteries with many types, each with their own benefits and challenges. Numerous changes have been made to the anode and cathodes to improve stability, power capacity, recharge cycles and cost. Recent efforts have focuses on reducing or removing cobalt. Capacity has grown about 5% per year and general stability has improved. I remember reading articles like this years ago where they talked about using LFP cathodes to improve the stability of batteries. Today LFP batteries are used in some Teslas and probably other vehicles. https://arstechnica.com/science/2021/05/eternally-five-years-away-no-batteries-are-improving-under-your-nose/ https://arstechnica.com/science/2021/05/eternally-five-years...
gameswithgo 5y ago
The cynicism for battery teach research is misplaced. In our lifetimes we have seen real enormous strides in battery technology actually go into production. LFP batteries are now in actual Teslas, provider a cheaper/safer/simpler option for lower range cars that depend on fewer exotic materials/mining. Sodium batteries are in the pipeline. Sulfur batteries may or may not make it too.
lordnacho 5y ago
The nature of science is disappointment, no? Maybe this will work... Nope. Maybe this other way? Nope. Now and again there's an actual advance and we rejoice, but if you keep an eye on cutting edge stuff it's got to happen a lot that some promising lead leads nowhere.
- rzzzt 5y ago
  Reporting could be delayed until the advance happens. Even better if I can buy it in a store at that point.
  - Fordec 5y ago
    I'll take "How we end up with scientists running around in circles making the same mistakes over and over." for $500. If you goal is to learn about things once they're stable and working, I suggest drop reading science journalism from your schedule and just start window shopping at electronics stores.
    - rzzzt 5y ago
      OK, I was thinking more of summaries of summaries of university news portal announcements on tech sites (which this one is not). I am not against academic publications, scientists should definitely be acquainted with what is happening in their field.
scythe 5y ago
>Electrochemical characterization and post-mortem spectroscopy/ microscopy studies on cycled cells reveal an altered redox mechanism that reversibly converts monoclinic sulfur to Li2 S without the formation of intermediate polysulfides for the entire range of 4000 cycles. The development of unconfined high loading sulfur cathodes in Li–S batteries employing carbonate- based electrolytes can revolutionize the field of high energy density practical batteries. [italics mine] These are bold claims. You don't hear that every day. Polysulfides have been an accepted fact of life in Li-S batteries forever.

perlgeek 5y ago

I haven't read the whole thing yet, and I'm not really a battery expert, but a battery needs to check really many boxes to be viable in a commercial product. Among these are: ability to mass produce, resistance to mechanical stresses, safety, peak performance, low auto-discharge, ability to recycle, energy density, charge cycles, efficiency, availability of materials, operational temperature range, storage temperature range. The latter criteria seem to be well addressed in the paper, the first few not really, or only tangentially (based on a quick ctrl+f for some of the key words).

deleted 5y ago
[deleted]

scythe 5y ago

They successfully used an electrolyte that has been refusing to work for the last 20 years of research on the topic. That's pretty good. Carbonate (ester) electrolytes are unparalleled in stability. But the abstract says that they're made using sulfur stabilized by[1] carbon nanofibers[1]. Great: now make a million of them. 1: EDIT: nanofibers stabilize the sulfur, but it is not encapsulated. The phrasing "within" in the abstract threw me for a loop.

formvoltron 5y ago
Engineering seems easier to improve than science.
- upofadown 5y ago
  It does? Most things fail in implementation.
photochemsyn 5y ago
Here's the step-by-step production they used, it doesn't seem implausible that this could be scaled up in a factory setting. Maybe a modular approach would work, i.e. you might have 100 production lines running simultaneously, each one running the following ~8 steps: Material synthesis Synthesis of CNFs. The free-standing CNFs were made by electrospinning. Typically, 10 wt% polyacrylonitrile, was added to DMF and stirred overnight to form a polymeric solution. This solution was then loaded into a Becton Dickinson 5 mL syringe with a Luer lock tip and an 18-gauge stainless steel needle (Hamilton Corporation). The syringe with the needle was connected to a NE-400 model syringe pump (New Era Pump Systems, Inc.) to control the feeding rate of the solution. The grounded aluminum collector was placed 6 in. from the tip of the needle. Electrospinning was performed at room temperature with a relative humidity below 15%. A potential difference of 7–8 KV (Series ES -30 KV, Gamma High Voltage Research, Inc.) was applied between the collector and the tip of the needle. The flow rate of the solution was kept constant at 0.2 mL h−1. The as-spun nanofibers were collected and stabilized in a convection oven at 280 °C for 6 h in air atmosphere. The stabilized nanofiber mats were then placed in alumina plates and carbonized in a nitrogen environment up till 900 °C at a ramp rate of 2.5 °C min−1 and then activated under CO2 flow for 1 h in a horizontal tube furnace (MTI. Corp). The furnace was then cooled at 2 °C min−1 until it reached room temperature. Monoclinic γ-sulfur deposition on CNFs. The free-standing CNF mats were pun- ched with stainless steel die (φ = 11 mm) and dried at 150 °C overnight under vacuum. The CNF discs were then weighed and placed in an in-house developed autoclave (Stainless steel 316) and subjected to 180 °C for 24 h in an oven. The autoclave consisted of a sulfur reservoir at the bottom and a perforated disk for placing electrodes at the top. After 24 h the autoclave was cooled to room tem- perature slowly in a span of 6–8 h. The electrodes were weighed and transferred in an Argon-filled glove box via overnight room temperature vacuum drying in the antechamber for battery fabrication.

known 5y ago

deleted 5y ago

[deleted]