A surprising breakthrough could help sodium-ion batteries rival lithium—and even turn seawater into drinking water. Scientists discovered that keeping water inside a key battery material, instead of removing it as traditionally done, dramatically boosts performance. The “wet” version stores nearly twice as much charge, charges faster, and remains stable for hundreds of cycles, placing it among the top-performing sodium battery materials ever reported.
  • apftwb@lemmy.worldEnglish
    201·
    15 hours ago

    the strategy of retaining crystal interlayer water yielded a specific capacity of 280 mA h g−1 at 10 mA g−1, one of the highest capacities reported for SIB cathodes in literature.

    BTW its worth noting how far this is from market. Currently these batteries are basically just jars with chemicals.

    https://pubs.rsc.org/en/Content/ArticleLanding/2025/TA/D5TA05128B

    https://www.rsc.org/suppdata/d5/ta/d5ta05128b/d5ta05128b2.mp4

    • finalarbiter@lemmy.dbzer0.comEnglish
      7·
      14 hours ago

      mAh/g (milliamp-hours per gram) is a similar unit, but it’s missing the voltage term. We can do a little dimensional analysis here to translate between them. Power = Current * Voltage, so you’d multiply this (CurrentTime)/(Weight) value by the nominal voltage of the cell to get to (PowerTime)/(Weight). So it is essentially still a measurement of capacity, but in terms of current instead of power.

      Phone batteries are often specified in units of Current*Time (e.g. milliamp-hours), but I’m not sure why.

      • apftwb@lemmy.worldEnglish
        2·
        6 hours ago

        multiply this (Current x Time)/(Weight) value by the nominal voltage of the cell to get to (Power x Time)/(Weight).

        This is the part that annoys me. The nominal voltage could vary between different batteries. 200Ah/g means different capacity for a 6v battery verses a 48v battery. I’m guessing battery scientists are using standardized nominal voltages for these tests or are seeing the same Ah/g capacity at different voltages (that I may have simply missed in the paper because I skimmed it and I don’t claim any deeper knowledge on battery research)

      • Wispy2891@lemmy.worldEnglish
        101·
        13 hours ago

        I’m not completely sure why

        I think it’s marketing

        5000 mAh is much a bigger number than 19 Wh and marketing loves huge numbers

        Kinda like BMW did with the i3.

        In 2013 Tesla was selling a model with a 60 kWh battery so BMW had the genius idea to install a 20 kWh battery BUT refer to it as “60 Ah” battery.

        Tesla introduced the 90 kWh battery? BMW responds with a 94 Ah battery (28 kWh)

        Newest Tesla has 100 kWh battery now? BMW has 120 Ah battery (38 kWh)

        “See? Higher number!”, says the marketing

        And in order to have a comparable range number they had to implement heavy weight reduction techniques like using carbon fiber for the body, negating any cost saving from the smaller battery AND giving the owner a total loss after small collisions as it shatters instead of bending

        • Tim@lemmy.snowgoons.roEnglish
          25·
          9 hours ago

          That’s an incredibly longwinded way of saying “mahh Tezlur burns three times as much ‘clean coal’ per mile as a commie BMW, yee-haw”.