Lower-Energy Energy Storage System (LEESS) Component Evaluation

Jeffrey Gonder, Jonathon Cosgrove, Ying Shi, Ahmad Pesaran, A. Saxon

Research output: NRELManagement


Alternate hybrid electric vehicle (HEV) energy storage systems (ESS) such as lithium-ion capacitors (LICs) and electrochemical double-layer capacitor (EDLC) modules have the potential for improved life, superior cold temperature performance, and lower long-term cost projections relative to traditional battery storage systems. If such lower-energy ESS (LEESS) devices can also be shown to maintain high HEV fuel savings, future HEVs designed with these devices could have an increased value proposition relative to conventional vehicles. NREL's vehicle test platform is helping validate the in-vehicle performance capability of alternative LEESS devices and identify unforeseen issues. NREL created the Ford Fusion Hybrid test platform for in-vehicle evaluation of such alternative LEESS devices, bench testing of the initial LIC pack, integration and testing of the LIC pack in the test vehicle, and bench testing and installation of an EDLC module pack. EDLC pack testing will continue in FY15. The in-vehicle LIC testing results suggest technical viability of LEESS devices to support HEV operation. Several LIC configurations tested demonstrated equivalent fuel economy and acceleration performance as the production nickel-metal-hydride ESS configuration across all tests conducted. The lowest energy LIC scenario demonstrated equivalent performance over several tests, although slightly higher fuel consumption on the US06 cycle and slightly slower acceleration performance. More extensive vehicle-level calibration may be able to reduce or eliminate these performance differences. The overall results indicate that as long as critical attributes such as engine start under worst case conditions can be retained, considerable ESS downsizing may minimally impact HEV fuel savings.
Original languageAmerican English
Number of pages9
StatePublished - 2014

NREL Publication Number

  • NREL/MP-5400-62853


  • capacitors
  • component evaluation
  • energy storage
  • hybrid vehicles
  • lithium ion
  • lower-energy energy storage systems


Dive into the research topics of 'Lower-Energy Energy Storage System (LEESS) Component Evaluation'. Together they form a unique fingerprint.

Cite this