Super Capacitors for Power Storage

"...supercapacitors have a longer lifetime than secondary batteries, but their lifetime is not infinite. The basic end-of-life failure mode for a supercapacitor is an increase in equivalent series resistance (ESR) and/or a decrease in capacitance. The actual end-of-life criteria are dependent on the application requirements. Prolonged exposure to elevated temperatures, high applied voltage and excessive current will lead to increased ESR and decreased capacitance. Reducing these parameters will lengthen the lifetime of a supercapacitor. In general, cylindrical supercapacitors have a similar construction to electrolytic capacitors, having a liquid electrolyte inside an aluminum can sealed with a rubber bung. Over many years, the supercapacitor will dry out, similar to an electrolytic capacitor, causing high ESR and eventually end-of-life."^

See also:

• http://www1.cooperbussmann.com/pdf/35f489ea-89f2-4089-bbe3-9432cd21f9be.pdf Excellent real world overview of Super Cap Applications.
• http://ka7oei.blogspot.co.nz/2013/05/lithium-iron-phosphate-lifepo4.html Cell imbalance issues in a multicell battery and a circuit to prevent it. This is for batteries, but may apply to multi-cell supercap power storage as well.+
• http://www.youtube.com/watch?v=KL1N_ThFkBc "Slurp" charge phones: Charge super caps for 5 minutes, charge cell phone from that for 18 minutes.
• Maxwell have a 2V85 3k4F high capacity ultracapacitor. It uses Maxwells Advanced Shock and Vibration technology.
  http://www.maxwell.com/products/ultracapacitors/products/k285-series Data sheet
  http://www.maxwell.com/products/ultracapacitors/products/engine-start-module/ Truck "battery" - 12 x 3000F !!!
  http://www.maxwell.com/products/ultracapacitors/docs/1014627_boostcap_product_guide.pdf Product guide - 50+ pages
• https://www.youtube.com/watch?v=1Ce2au3PWnI Step by Step process for making super capacitors. Requires active material: Graphene 4m/ml or Activated Carbon seperated by something like paper towel from a metal foil and an electrolyte solution. Aluminum with Sodium Hydroxide, Nickle with Potassium Hydroxide. Foil, coat with Graphene Oxide, dry, scrape off excess. Other bit of foil, dip coated in carbon solution, dry, scrape off excess. Seperator between soaked with electrolyte.
  https://www.youtube.com/watch?v=hFUOsZ0LSkQ Cheap and easy process to make Graphene. Just put a negative stainless steel electrode wrapped in paper towel and positive graphite electrode into 0.4 molar Sodium Sulphate solution. Apply 2 volts for a couple minutes, then 10 volts for 30 minutes. Sulphate ions are consumed and process then stops. Filter with distilled water to remove excess. Grind, homogenize, or vibrate in sonic cleaner to mechanically break down the result.

PICList 2024 contributors: o List host: MIT, Site host massmind.org, Top posters @none found - Page Editors: James Newton, David Cary, and YOU! * Roman Black of Black Robotics donates from sales of Linistep stepper controller kits. * Ashley Roll of Digital Nemesis donates from sales of RCL-1 RS232 to TTL converters. * Monthly Subscribers: Gregg Rew. on-going support is MOST appreciated! * Contributors: Richard Seriani, Sr.

  .