Automotive Electrochemical Power Systems

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Automotive Electrochemical Power Systems
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Vehicular Batteries Are Widely Used Vehicular
Fuel Cells Are Widely Discussed

• All batteries contain the anodic reactant , but
  not necessarily the cathodic reactant, which can
  be O2
• In fuel cells, the anodic reactant is stored in
  an external reservoir
• The apparent, but not the true, power density of
  fuel cells is higher than that of batteries
• When the weight (or volume) of the
  reactant-reservoir, plumbing and fuel pumps are
  added, fuel cells loose their apparent advantage
• The successful fuel-efficient hybrid cars have
  batteries, not fuel cells

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Why GM Lost Market Share

• Because of the low taxation of gasoline in the
  US and its high taxation in Japan
• While engineering-led Honda (with Sanyo) and
  Toyota (with Matsushita-Panasonic) engineered the
  nickel-metal hydride battery for hybrid cars,
• Marketing-led GM aimed, through its Hy
  Wire/Sequel project, at sustaining its image as
  the advanced engineer, building a hydrogen
  fueled, fuel cell-powered dream car

GM Hy-Wire PEFC car
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GMs Statement (Verbatim ) While GM is serious
about delivering innovative solutions for the
environment and safety, were just as serious
about performance. And we havent forgotten that
cars should still be fun. People are passionate
about driving. And nothing could be more fun to
drive than the Sequel. Wheel hub motors deliver
unprecedented torque and instant acceleration,
providing a unique driving experience. As GM
chairman and CEO Rick Wagoner puts it, Sequel
excites the driving enthusiast within us. Hows
that for reinvented?
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Problems of Vehicular H2/O2 Fuel Cells

• Because of poor mass transport in the cold cell,
  starting and restarting require pre-heating
• Response to increase or decrease in power demand
  is slow
• Cost the membrane, the platinum alloy catalyst,
  the seals and the containment are much too
  expensive
• There is no hydrogen fuel infrastructure

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Electrode Reactions of the Hybrid Car Batteries

• Anode (metal-hydride) (LaNi5 lattice structure)
  MH ? M H e-
• M (rare earth) (transition metal)5
• Transition metal Ni3.2Co1.0Al0.2Mn0.6  
• Cathode (hydrated nickel oxide with carbon)
• NiOOH H e- ? Ni(OH)2
• Cell Ni(OH)2 M ? NiOOH MH

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Design Principles of Hybrid Vehicle Battery
Materials

• Cycle-life To prolong the cycle life, only
  protons and electrons (hydrogen atoms) are added
  or stripped in the reduction/ oxidation cycles.
  Adding or stripping hydrogen atoms does not
  change the phase or the morphology
• Power density and rapid charging High proton
  (hydrogen) permeability provides for rapid
  charging and discharging (i.e. power)

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Current RDE Objectives of the Hybrid Electric
Vehicle Consortia

• Lower the cost of the electrode materials
• Lighter electrodes for a higher energy density
  battery

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A High Risk, High Payoff Research Option An Air
Cathode for a Vehicular Battery

• Proposed approach Improve the efficiency, lessen
  the sensitivity to poisoning and reduce the cost
  of the O2-electroreduction catalysts by replacing
  the platinum alloys with nature-mimicking
  synthetic 3-Cu atom (or 3-Ag atom) cluster-based
  catalyst
• Impact Air cathode would provide for a much
  lighter, much lower cost power system