The Florida State University Institute on Energy Systems, Economics and Sustainability

Transcription

1 The Florida State University Institute on Energy Systems, Economics and Sustainability Electrical energy storage via chemistry: drivers and challenges Albert Migliori Los Alamos National Laboratory and the National High Mgentic Field Lab

2 Accuracy of our ability to predict technology "Who the hell wants to hear actors talk?" H.M. Warner, Warner Bros., "Television won't be able to hold on to any market...people will soon get tired of staring at a plywood box..." Darryl Zanuck, 20th Century Fox, "There is no reason anyone would want a computer in their home," Ken Olsen, founder of mainframe-producer Digital Equipment Corp., I said to my brother Orville that man would not fly for 50 years. Ever since, I have distrusted myself and avoided all predictions. - Wilbur Wright "There's no chance that the iphone is going to get any significant market share. No chance." -- Steve Ballmer, CEO of Microsoft

3 Renewable energy must be stored when available and recovered when needed Renewable(wind) availability in New Mexico Electrical energy use in New Mexico We know how to make electricity from sunlight. We know how to make electricity from wind. It will be some time before we develop the technology to store enough renewables to make 25% renewable energy penetration of the grid possible.

4 Distributed electrical energy storage and the future? From: Department of Energy Report of the Basic Energy Sciences Workshop for Electrical Energy Storage (April, 2007): Revolutionary breakthroughs in electrical energy storage have been singled out as perhaps the most crucial need for this nation s secure energy future. And another from BES on energy storage: A systematic, highly coordinated research effort... is critically needed to elucidate.. fundamental atomic- and molecular-level issues. Try this with your photovoltaics!

5 Applications and effects of distributed energy storage Distributed electrical energy storage on the utility grid in massive amounts helps not only renewable energy utilization but: Keeps nuclear plants at full capacity, minimizing radioactive waste per unit of electricity produced. Keeps coal plants at full capacity, minimizing atmospheric carbon per unit of electricity produced Provides dual-use storage when your electric car is parked and plugged in to the grid. Minimizes need for new transmission lines (electrical equivalent of growing it locally). Stabilizes the grid and reduces outages. 4/21/10 5

6 Necessary ingredients for energy storage solutions Technology Science Engineering Materials Economics Hidden traps The real costs revealed Environmental Let s not make a bigger mess Legislative Legislative protection for new technology Legislation that matches new technology 4/21/10 6

7 Energy storage-chemistry will be a solution (1 kwh=3.6mj = $0.10) Fuels: 4-40 kwh/kg (x Thermal Efficiency= 0.8 to 8 kwh/kg if burned). This is very hard to ignore. Especially in fuel cells. Gasoline: 12 kwh/kg Zn-air battery: 0.45 kwh/kg There are a few hundred more axes: cost/joule size/joule loss/day utilization factor, power/kg,.. Li-ion battery : 0.15 kwh/kg Supercapacitor: 0.02 kwh/kg Antimatter 25,000,000,000 kwh/kg

8 Zn-air battery and the electric car Gasoline car Engine, transmission, driveline, exhaust gasoline 220 miles 0-60 in 3.9 s $100,000.00??? energy conversion storage content efficiency weight range Zn-air Battery = 1 x 0.9 x 0.9 = 240 miles Gasoline= 26 x 0.2x 0.2= 300 miles Electric car Battery Electric motor

9 Chemistry is good Entire system is expensive battery Cheap fuel tank-only converter is expensive Pumped hydro flywheel magnet Fuel cell/electrolyzer Compressed air capacitor 4/21/10 9

10 What is it we at LANL/FSU/CNSE/UF are trying to do? The goal is to park and recover electrical energy in chemical bonds (make fuel from electricity). Tony Burrel's theorem: If the energy from electric fields is not transferred to chemicals, then we are not storing electrical energy. Seems obvious, but... Consequence: pressure, heat, etc. do not count. We are not after better catalysts. What we are after is making the electrical energy in as nearly equal as possible to the chemical energy out.

11 Voltage Example: Making chemicals from electricity--a science problem, not a technology problem. 2 H 2 + O 2 (Hydrogen) Energy lost to splitting O 2 0.2V Losses to Gas crossover 0.1 V Water to steam 0.25 V Other losses 0.25V So 1.5 V in yields 0.7 Volts out 0.7 V Electricity out 1.5 V Electricity in (1.25 volts if we start with steam) H 2 O (water) The overpotentialgoal is to reduce this H 2 O (water)

12 Alternatives to hydrogen: carbon capture? Much innovative work has been done on direct conversion of bond energy to electricity (the fuel cell) but the reverse cycle (electrolysis) has not received as much attention. N 2 + 6H+ + 6e- 2NH 3 CO 2 + 6H+ + 6e- CH 3 OH + H 2 O 4H+ + 4e- 4H 2 We will attack the electrode problem

13 All I know about batteries

14 Solutions to distributed electrical energy storage cannot be left to one team

15 You don t actually have to do chemistry! - Figure : Coarse-grained model for nanotube forest with electrolyte TEA+ Figure : Snapshot of molecular dynamics simulation on a carbon nanotube with BF4-/TEA+/PC electrolyte BF4-

16 One approach: make it simple to promote understanding Focus on the electrocatalyst only Use thin metal films (thickness of order electron DeBroglie wavelengths) On thick substrates In simple electrolytes Simple enough to model accurately Simple enough to make reproducible Large enough to enable many measurements Promoting mixing of electronic properties Making possible control of electric fields