Publication Authors

Marium Rasheed
Doctoral Student

Hongjie Wang
Assistant Professor

Regan Zane
Faculty

Dragan Maksimovic
Faculty

Khurram Afridi

Gregory Plett
Faculty

M. Scott Trimboli
Doctoral Student

Composite Hybrid Energy Storage System utilizing Capacitive Coupling for Hybrid and Electric Vehicles

An innovative architecture is presented that combines energy-dense and power-dense battery packs through a supercapacitor that provides capacitive coupling and a low-power DC-DC converter that provides energy balancing. A sizing algorithm is developed to optimize the design of such systems for plug-in hybrid and battery electric vehicles (PHEVs and BEVs). The proposed composite architecture extends vehicle range and battery lifetime by fully utilizing the capabilities of energy-dense and power-dense battery chemistries. A power-dense battery is coupled to an energy-dense battery using a small supercapacitor module that naturally distributes the system current between the two packs, requiring no additional contactors or full-power processing DC-DC converters. The proposed algorithm provides a tool for designing the composite architecture to achieve maximum weight reduction under given conditions for both ideal and practical scenarios. A design example is provided based on a PHEV with 68-mile range using the US06 drive cycle. The design achieved a 42% weight reduction when compared to a similar design with a conventional single chemistry battery system. Experimental results of a 1.5 kW, 0.2 kWh small-scale prototype with 25 Ah NMC and 2.9 Ah LTO battery cells and a 30 F supercapacitor verify the natural distribution of system current between the energy-dense and power-dense packs.