Carbonized Cellulose Fiber and Composites for Ultrafast Electrochemical Capacitors

Background

Filtering capacitors are ubiquitous components used in power conversion and conditioning for electronic devices, industrial power supplies, electrified transportation, and renewable energy generation. Aluminum electrolytic capacitors (AECs) have typically been used for these applications, particularly when large capacitance (>10µF) is needed. However, AECs have many drawbacks including their bulky size, poor lifetime, sensitivity to temperature and voltage polarity, and having a large equivalent series resistance (ESR). These limitations significantly reduce their effectiveness and performance. There is a need for new filtering capacitors with reduced size and more reliable and improved performance.

Invention Description

Researchers at Arizona State University have developed a novel ultrafast electrochemical capacitor (EC) for ripple current smoothing and filtering capacitor applications. The capacitor is made using carbonized cellulose (CC) sheet-based composite electrodes. The cellulose sheets (e.g., tissue papers) can be carbonized by a rapid pyrolysis process in a preheated furnace as the electrode scaffold, on which another nanomaterial is coated to form a composite. These fabricated ECs have the potential to substitute the bulky aluminum electrolytic capacitors for current smoothing and pulse power applications.

Potential Applications

  • Consumer electronics
  • Pulsed power applications (e.g., water treatment, defense)
  • Renewable energy generation
  • Electrified transportation
  • Industrial power supplies

Benefits and Advantages

  • Improved performance – large capacitance & fast frequency response
  • Compact size – small & flexible format
  • Increased reliability – prevents voltage spikes which can cause damage
Patent Information: