Advanced Battery Research, Development, and Testing

Argonne plays a major role in the US Department of Energy’s (DOE’s) energy storage program within its Office of Vehicle Technologies. Activities include:

Developing advanced anode and cathode materials under DOE’s longer term exploratory R&D program
Leading DOE’s applied R&D program focused on improving lithium-ion (Li-Ion) battery technology for use in transportation applications
Developing higher capacity electrode materials and electrolyte systems that will increase the energy density of lithium batteries for extended electric range PHEV applications
Conducting independent performance and life tests on other advanced (Li-Ion, Ni-MH, Pb-Acid) batteries.

Argonne’s R&D focus is on advanced lithium battery technologies to meet the energy storage needs of the light-duty vehicle market.

Li-Ion Battery Challenges

Li-Ion batteries offer several advantages over other types of rechargeable batteries, including lighter weight, higher power and higher energy. They offer major advantages for hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs), as well as other applications. As battery developers work to create larger lithium-ion batteries, however, they are faced with four main challenges: safety, cost, life and performance (power and energy) over a wide temperature range (-30 to 52°C).

Scientists and engineers at Argonne work together to solve these challenges through the discovery and development of new lower-cost cell materials and cell chemistries that simultaneously improve battery performance, life and safety.

Li-Ion Battery Safety Issues

The safety issues associated with Li-Ion batteries grow as the cell sizes increase to those needed for HEVs, PHEVs, and EVs (electric vehicles).

Argonne is working to improve the safety of lithium-ion cells and batteries by first studying the thermal properties of Li-Ion materials, components, and cells to determine the mechanisms that control thermal runaway.

These studies form the basis for the development of safer lithium-ion cell materials, such as

Advanced inter-metallic and nano-phase lithium titanate negative electrode materials that operate further away from the potential of metallic lithium
New electrolyte additives and systems that form more stable passivation films at the electrode/ electrolyte interfaces and retard flammability
More stable composite-structure mixed-metal oxide positive electrode materials that produce less heat during thermal excursions, and significantly improve cell performance and life.

LI-Ion Battery Life and Performance

Argonne conducts accelerated cell aging and extensive detailed diagnostic studies, along with electrochemical modeling, to establish the mechanisms that control power fade and capacity loss in different Li-Ion cell chemistries. These tests have led to more stable mixed-metal oxide cathode materials, surface coatings, and electrolyte additives that stabilize the electrochemically active interfaces to improve life. In addition, diagnostic and modeling studies on Li-Ion cells examine the causes of poor low-temperature performance.

Battery Cost Studies

Meeting DOE/USABC (United States Automotive Battery Consortium) cost goals is another major barrier for all energy storage systems. To address this barrier, Argonne researchers developed software tools to design Li-Ion HEV, PHEV, and EV cells and batteries. These tools are used to estimate cell and battery costs as a function of cell materials and production rate. This methodology is used to study cost reductions associated with new cell materials and components, including things like flexible cell packaging, as well as the impact of using the more stable and lower-cost cell materials that are being developed at Argonne.

Higher Energy Density Materials

In 2007, DOE initiated several material R&D projects at Argonne that focus on increasing the energy density of lithium batteries. These include:

Stabilization of lithium metal anodes
Research on new high-capacity cathode materials that would work with lithium metal anodes, and
Stabilizing conventional cathode materials to facilitate operation at higher voltages, where they can deliver higher capacity per unit weight and volume.

In addition, methods of stabilizing electrolytes at higher voltages are being pursued.

Battery Test Facility

In 1976, Argonne became home to DOE’s first independent battery test laboratory for evaluating advanced battery technologies for use in transportation applications. The Battery Test Facility is a computer-operated test laboratory where cells, modules, and complete battery systems are subjected to performance and life tests under simulated real-world conditions. In addition, accelerated aging tests are conducted to provide early predictions of life under normal operating conditions.

August 2008