Nanostructures for Electrical Energy Storage (NEES)

The Rubloff group has been supported by NEES (Nanostructures for Electrical Energy Storage), an Energy Frontier Research Center (EFRC) established and funded by the Department of Energy’s Office of Science, Basic Energy Sciences from 2009 to 2020.  Rubloff has led the NEES EFRC since its inception in 2009. The Rubloff group contributes widely across the Center as its materials synthesis approaches (particularly atomic layer deposition, ALD) are exceptionally well suited to the high aspect ratio nanostructures (tall, narrow, and densely spaced) required while the real-time, in-situ measurement provide excellent insights at the nano and meso sale into these systems.

The group’s highlight capability is in atomic layer deposition (ALD), which employs CVD precursors in alternating self-limiting saturation doses onto a 3D surface. The resulting characteristics include unprecedented thickness control and uniformity even over high aspect ratio topography and into deep narrow pores.  In seeking thin ion storage layers formed over surface areas enlarged by 3D topographies, ALD is unique.  Accordingly the group has collaborated widely across NEES to make advanced nanostructured electrodes with 3D ALD electrode materials for both ion storage an electron transport.  Topographic scaffolds range from massively parallel nanopore arrays to CNT sponges to cellulose.

Over the last several years the group has shifted priorities to solid state battery structures, recognizing that a solid electrolyte is a safe (nonflammable) electrolyte, as increasingly needed, and that all-solid systems are more amenable to diagnostics than liquid electrolytes (particularly the characterization methods compatible with its thin film processing).  At the same time, the Rubloff group and NEES are both focusing on the 3D patternability enabled by thin film processing to create well controlled 3D structures in flexible form factors, opening the door to viable 3D solid state batteries for a variety of applications.