New Capacitor: D Cell Form Factor & 6 Wh/kg Energy Density

  • Thread starter Thread starter anorlunda
  • Start date Start date
  • Tags Tags
    Capacitors
Click For Summary
SUMMARY

The latest capacitors, specifically the MaxWell brand, feature a D cell form factor with an energy density of 6 Wh/kg and a power density of 4600 W/kg, significantly outperforming traditional lead-acid batteries. With a cycle life of over 500,000 cycles and a maximum leakage current of just 0.3 mA, these capacitors are revolutionizing energy storage applications. The specifications include a rated voltage of 2.7V, rated capacitance of 350F, and an equivalent series resistance (ESR) of 3.2 mΩ, showcasing substantial advancements in capacitor technology.

PREREQUISITES
  • Understanding of capacitor specifications and performance metrics
  • Familiarity with energy density and power density concepts
  • Knowledge of ESR (Equivalent Series Resistance) and its implications
  • Basic principles of energy storage technologies
NEXT STEPS
  • Research the applications of supercapacitors in modern energy systems
  • Explore advancements in capacitor technology over the last two decades
  • Learn about the comparison between supercapacitors and traditional batteries
  • Investigate the impact of ESR on capacitor performance in high-current applications
USEFUL FOR

Engineers, researchers, and product developers in the fields of energy storage, electronics, and battery technology will benefit from this discussion, particularly those interested in the latest advancements in capacitor technology.

anorlunda
Staff Emeritus
Science Advisor
Homework Helper
Insights Author
Messages
11,326
Reaction score
8,755
I'm impressed by the specifications of the newest capacitors. They are sold in the form factor of a D cell battery for at little as $8 each. I have no question. I'm just amazed at how fast that technology is improving. It may be time to consider applications for capacitors that we pooh-poohed before as unrealistic.

Capacitor versus lead-acid battery
Energy density 6 Wh/kg versus 33-42 Wh/kg.
Power density 4600 W/kg versus 180 W/kg.
Cycles 500000 versus 500.
Leakage 0.3 mA versus 3-20%/month self-dischargea

Here are some specs quoted for the capacitors.
  • Brand：MaxWell33-42
  • Rated Voltage：2.7V
  • Rated Capacitance：350F
  • Capacitance Tolerance：0%~10%
  • ESR(DC)：3.2mΩ
  • Maximum Continuous Current (at 15℃)：35A
  • Maximum Peak Current：220A
  • Maximum Leakage Current (72hrs/mA)：0.3mA
  • Power Density (W/kg)：4600
  • Maximum Energy (Wh)：0.35
  • Energy Density (Wh/kg)：5.9
  • Operating Temperature range：-40℃~65℃
  • Storage Temperature range：-40℃~65℃
  • Weight (g)：63.3
  • Size (ΦD×L/mm)：33.3×61.5
  • Cycle Life：≥500000
 
  • Like
Likes   Reactions: NascentOxygen, jim hardy and Thewindyfan
Engineering news on Phys.org
I too am amazed by the energy that can be packed into such a small package as compared to say 20 years ago. Often times these super capacitors are not suitable for anything except memory backup or something similar due to a high ESR but even that is shrinking down.
 
  • Like
Likes   Reactions: Thewindyfan
I'm impressed.
The .0035 ohm esr is calculated after 15 seconds at a 35 amp load. In the "olden days" you couldn't get all the charge at a high current.
Just for perspective, 350F means 1 amp for 35 seconds drops 0.1v. That's wild!