Publication Detail

"Advanced Batteries for Vehicle Applications,"  chapter in Encyclopedia of Automotive Engineering

UCD-ITS-RP-14-25

Reprint

Sustainable Transportation Energy Pathways (STEPS), Plug-In Hybrid & Electric Vehicle Research Center

Suggested Citation: A. Burke (2014) "Advanced Batteries for Vehicle Applications" in D. Crolla, D.E. Foster, T. Kobayashi and N. Vaughan (Eds.) Encyclopedia of Automotive Engineering, John Wiley & Sons Ltd: Chichester. DOI: 10.1002/9781118354179.auto064. Published 4/22/2014. 

This chapter is concerned with the research and development on advanced batteries for plug-in electric vehicles in the next 10–20 years. The primary motivation for the development of the advanced batteries is to permit the design of electric vehicles having ranges comparable to conventional ICE vehicles—300–500 miles. By advanced batteries are meant cell chemistries having energy densities significantly higher than those presently available. These chemistries include (i) lithium-ion cells using layered–layered composites of metal oxides in the cathode, mixtures of carbon and silicone in the anode, and advanced electrolytes permitting cell voltages of 4.5–5 V and (ii) metal–air cells utilizing zinc or lithium in the anode and an air cathode. It is expected that some of the new lithium chemistries will be the first of the advanced battery technologies to be marketed in the next 5–10 years. The metal–air batteries are much further in the future and likely will be required to approach the 300–500-mile range goal.

Spreadsheet models of cells using the various chemistries were developed to calculate their energy densities and power capability. In the case of the advanced lithium-ion chemistries, it was found that the largest improvements in cell performance will result from significant increases in cathode charge capacity mAh/g and increases in the cathode voltage. The model results for the advanced lithium-ion cells indicate that energy densities of 350–400 and 750–800 Wh/kg (unpackaged) are possible at power capabilities suitable for vehicle applications. With improvements in plug-in vehicle design (lower weight and energy consumption-Wh/mi), the advanced lithium batteries could be used in 250–300-mile range vehicles.

Zinc–air and lithium–air cells were also modeled to project their performance. Both metal–air systems were modeled using an aqueous electrolyte (KOH) and a carbon/catalyst air cathode. In the case of the zinc–air cells, the projected energy densities were 500–600 Wh/kg and 2000–2400 Wh/L (unpackaged) depending on the discharge time and air cathode current density assumed. The power capability of the Zn–air cells was relatively low in the range of 150–300 Wh/kg. The projected energy densities of the lithium–air cells were 2000–3000 Wh/kg and 2000–2500 Wh/L (unpackaged) depending on the resistance (Ohm-cm2) assumed for the anode protective film and the current density of the air cathode. In all cases for the lithium–air calculations, it was assumed that large reductions in the present high resistance of the anode protective film would occur in the future. The power capability of the lithium–air cells with the improved protective film was 1000–1500 W/kg, which was much higher than that for the Zn–air cells. The higher power capability of the Li–air cells is primarily due to their higher cell voltage.

Keywords: batteries; lithium; metal-air; electrolytes; 300 mile electric vehicles