3 ms·

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) elect

• 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.
  • scythe 5y ago
    Indeed, I read the abstract: >we stabilize a rare monoclinic γ-sulfur phase within carbon nanofibers and my mind jumped to "sulfur inside a nanotube again". But the sulfur isn't "within" the carbon nanofibers, as they later specify, and this is new. >We demonstrate that despite an exposed “un-confined” deposition of this sulfur phase on the host carbon material, the carbonate-based battery exhibits high reversible capacity The sulfur is in contact with the electrolyte. And it works! That's not supposed to happen, but now it does. So the process you described doesn't make carbon nanotubes, it makes nanofibers, which are much simpler (you don't need axial concentric planes).
  • derefr 5y ago
    So this is essentially a piece of carbon “cotton candy” that has sponged up some sulphur?