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Home , Pseudocapacitor, Supercapacitor

SupercapacitorSupercapacitor

Lab. of Conversion & Storage Materials

Produced by I. H. Kim Edited by S. B. Ma Directed by K. B. Kim Lab. of Energy Conversion & Storage Materials Comparison of Battery & Electrochemical //

Electrochemical Condenser Battery Capacitor Discharge time < second < a few minutes 0.3 ~ 3 hours Charge time < second second order hour order Specific 0.03 ~ 0.3 5 ~ 10 20 ~ 100 energy(Wh/kg) 0.05 0.05 ~ 5 50 ~ 250 (Wh/L) Specific power > 10 4 1000 ~ 2000 50 ~200 (W/kg) > 10 6 10 5 ~ 10 8 150 (W/L) Charge/discharge > 0.9 0.9 ~0.95 0.7 ~ 0.85 efficiency Cycle life > 10 6 > 10 5 < 1000

Lab. of Energy Conversion & Storage Materials for Electrochemical Capacitor & Battery //

Lab. of Energy Conversion & Storage Materials Electrochemical //

Lab. of Energy Conversion & Storage Materials Electrochemical Double Layer Capacitor (EDLC) //

Electrical Double Layer Capacitor (EDLC) Charge stored at /solution interface ; Charge separation at electrical double- layer (EDL) Non-faradaic process 2 ; Cdl : ∼30 μF/cm materials with high surface area

Lab. of Energy Conversion & Storage Materials (or ) //

e- A - e Supercapacitor (or Pseudocapacitor) + - Faradaic process(Pseudocapacitance) + Non- - - e e faradaic Process(EDL) ; Electrochemical surface process or bulk redox process e- e- Pseudocapacitance (C p) + Electrical double- layer (Cdl ) ; C ≒ 10 to 100 × C e- e- p dl Conducting Polymers,

Metal oxideH+ Metal

Lab. of Energy Conversion & Storage Materials Electrode Materials for Requirements //

· Low raw material cost & easy fabrication processes · High electrochemical reactivity, fast redox reaction · High electrical conductivity ( ⇒ power density) ⇒ non-stoichiometric transition metal oxides · High specific area ( ⇒ energy density) > Energy Density  Specific Capacitance > Power Density  High Rate Capability

Lab. of Energy Conversion & Storage Materials Electrode Materials for Supercapacitors //

· RuO 2 (sol-gel method, ESD) : 650 ∼ 720 F/g

· MnO 2 (sol-gel method, electrochemical deposition etc.) : 100 ∼ 720F/g

· CoO x (sol-gel method) : ∼ 290F/g

· NiO x ( sol-gel method, electrochemical route, ESD) : ∼ 250F/g

· V2O5 (quenching of V 2O5 fine powder) : ~ 350F/g · Oxides : ∼ 200F/g

Lab. of Energy Conversion & Storage Materials Applications Automotive Applications //

Electric Vehicles (EV), Hybrid EV (HEV)

The use of ultracapacitors for generative braking can greatly improve the fuel efficiency of cars under stop-and-go urban driving conditions. Only ultracapacitors have both storage capacitance and high current handling capability to capture and store large amount of generated by braking within a short time and to release it again for re- acceleration. The generative braking has the potential to be one of the biggest applications for large-size ultracapacitors in the medium term. (high power density)

Lab. of Energy Conversion & Storage Materials Applications Load-leveling & Uninterruptible Power Systems (UPS) //

The ultracapacitor in the Uninterruptible Power System serves a load - leveling function by absorbing power surges and spikes and then releasing clean quality power essential for precision high-tech equipments. (high power density)

Instantaneous Power Current Interruption Supply Power back-up from Ultracapacitor

Load of Main Voltage (V)

Main Power Power Source

Time t Ultracapacitor Instantaneous Time Gap Protection of System Operation

Lab. of Energy Conversion & Storage Materials Applications Pulse Power Applications //

Unlike analog equipment that draws a steady current, a digital mobile telecommunication device loads the battery with short, heavy current spike during its transmit mode. If an ultracapacitor is added to the system, then it can take over the task of providing the intermittent pulse power while the battery functions only as a supplier of steady current. Users benefit from longer talk-time between charges and from the extension of battery-life. (high power density)

Lab. of Energy Conversion & Storage Materials