U N. Supercapattery: A Super Battery Approach. George Z. Chen

Transcription

1 U N Supercapatteries & Power Electronics Supercapattery: A Super Battery Approach George Z. Chen Department of Chemical and Environmental Engineering, and Energy and Sustainability Research Division University of Nottingham george.chen@nottingham.ac.uk Natural sponge Nanotubes sponge for electricity absorption Successful Prototype ca.1 cm 200 nm

2 specific power, W / kg UK Innovation Forum: Energy Storage, Birmingham, 28 Nov Electrochemical Energy Storage Principle: STORE chemical energy CONVERTER USE electrical energy Rechargeable Battery: STORE CONVERTER USE: medium energy & power Redox flow cell (inc. fuel cell ) : STORE >> CONVERTER USE: high energy, low power Supercapacitor (Electrochem. Capacitor) : STORE << CONVERTER USE: low energy, high power double layer supercapacitor large surface inert materials pseudo-supercapacitor/ supercapattery large surface redox active materials rechargeable battery redox flow battery specific energy, Wh / kg HI Becker, Patent, US , (1957). S Trasatti & G Buzzanca, J Electroanal Chem 29 (1971) A1. BE Conway, J Electrochem Soc 138 (1991)1539. J Owen, C&I, 17 Sept. 2001, p Capattery is a trademark of Evens, Inc., used for EDLC with activated carbon, but has received academic objections. Rudge et al., J. Power Source., 47 (1994) 89.

3 Current Current UK Innovation Forum: Energy Storage, Birmingham, 28 Nov Supercapattery Explained Supercapattery matches battery in energy capacity, and supercapacitor in power capability. 0 U min Battery Strategy Improving electrode kinetics: i. Charge transfer and transport. ii. Reversibility and conductivity. Type I Supercapattery: Supercapacitors (EC electrode EC electrode) (Pseudo-capacitance) Type II Supercapattery: Hybrid cells (EC electrode battery electrode) 0 0 U max Time 0 Potential U max 0 Potential Supercapacitor or Supercapattery (Type I) Supercapattery (Type II) Device Power/Energy (P/E) ratio: U max Supercapacitors: > 10,000:1 Batteries: < 2:1 Supercapatteries: 100:1 ~ 10:1 0 Potential Chen GZ, Abstract #559, 220 th ECS Meeting, Oct 2011

4 Materials & Electrodes Chen GZ et al, Adv. Mater., 12 (2000) Jin XB et al, Small, 3 (2007) Fabrication of electrodes: Screen printing (L) and rolling (R) Patent (2008) 6 mm CNT-PAn C - = F C + = 35.1 F = 26.5 F/cm 2 (world record) Q = 10.6 C/cm 2

5 Zero-Cost Engineering for Capacity Enhancement Asymmetrical SPs: PAn-CNT (+) HCl (1.0 M) CMPB ( ) Over-oxidation of PAn C P /C N : , C s, cell decreases by 7%. En s increases over 80%. Peng C et al, Energy Environ. Sci., 2010, 3, 1499

6 Prototype Supercapatteries Zhou XH et al, AIChE J, 58 (2012) 974. First prototype of the same in the world Patent (2011) 20 V 180 x 180 mm 2 (Multi-cell stack with bipolar plates)

7 Testing & Understanding 0.01 Hz Stack of supercapacitors water Effect of redox active impurities, e.g. O 2, Fe 2+ /Fe 3+, etc., Effect of charging time on selfdischarge OCV a bln( t c) Niu JJ et al, J. Power Sources, 135 (2004) 332. Zhou XH et al, AIChE J, 58(3) (2012) 974. Chae JH et al Green, 2 (2012) 41.

8 Supercapatteries in the Ragone plot Chae J-H et al, Proc. IMechE, Part A: J. Power Energy, 224 (2010) 479.

9 Grid Power Load Levelling Predicted dimensions of a bank of supercapatteries (150 MWh, 20 MW) with intelligent power electronic interface

10 Non-Intermittent Renewables Supercapatteries in Salt Caverns 660m salt cavern gas storage projects launched in the UK on16/2/ Impermeable salt wall, large volume, Free" aqueous electrolyte, high conductivity, high heat capacity, wide temperature range, and low environmental impact. In Jan. 2010, the author assessed a giant battery in deep salt cavern concept from the University of Queensland.

11 Self-Sustained Solar Home 100~200 W per panel Daily consumption of electricity by my family (4 people, 6 hrs in weekday evening, and 16 hrs at weekends): 10 3 kwh Power of solar panels on roofs of a 3-bed residential house (Full day use at weekend): 2 1 kw Storage capacity needed for 6 hr evening supply: < 5 kwh Specific energy of supercapatteries: 30 Wh/kg (aqu.) ~ 100 Wh/kg (org.) Weight: 170 ~ 50 kg (or 200~80 kg inc. packaging). Max. / Min. vol. (d =>1.5 kg/l): 140 L / 54 L 6~14 cm 50 cm Dimensions of a 5 kwh supercapattery

12 Supercapattery for Transport The Nottingham Supercapattery is being developed for cars, trams, cranes, elevators, etc, either as a standing alone or accelerating power source. The concept of a semi-electric bike that helps uphill riding. P.E. is one of the main reasons why many people use bicycles. A supercapattery bike that can offer high power for short period to assist uphill riding is possibly more attractive and much cheaper to buy. ( The work presented received funding from the EPSRC, and E.ON AG 2007 International Research Award Energy Storage, and the Follow-On Grant. Responsibility for the content of this report lies with the author.