(503f) Aqueous Based Cathode Slurries for Use in Three-Dimensional Lithium-Ion Batteries

Aqueous Based Cathode Slurries For Use in Three-Dimensional Lithium-ion Batteries

Derek C. Johnson, Matthew T. Rawls, and
Amy L. Prieto

Chemistry Department, Colorado State
University

Prieto Battery, Inc., Fort Collins, CO

                Traditional
two-dimensional planar based lithium-ion batteries have the inherent trade-off
between energy and power density.  If one
is designing a high power density cell, the electrode thickness is typically reduced
resulting in a decrease in energy density. 
Conversely, if the cell is designed for high energy density, power
density is diminished because of an increase in lithium-ion diffusion length as
a result of an increase in electrode thickness. 
The use of a three-dimensional (3D) architecture is intriguing because
it allows a significant decoupling of energy and power density.  This is accomplished because 3D architectures
allow the utilization of a third dimension without inducing damage or
instability into the electrodes.  Additionally,
a 3D architecture calls for the interdigitation of the negative and positive
electrodes thereby reducing the lithium-ion diffusion length by a factor of
10-100.  While the use of 3D battery
architectures promises a significant leap forward in terms of performance, many
technical challenges must be overcome in order to fabricate a functional
cell.  Our work is focused on using
electrodeposition to synthesize 3D anode structures to which a conformal
solid-state electrolyte coating is deposited. 
A significant challenge we have faced is the incorporation of a nanoparticle cathode slurry into the 3D structure without
damaging the solid-state electrolyte, thus causing a short.  The most pressing problem has been the
incompatibility of the slurry solvent with the solid-state electrolyte.  We thus have developed an aqueous based
slurry that when dried results in a low impedance, structurally robust positive
electrode that does not damage the solid-state electrolyte.  The solid-state performance of this electrode
with nanoscale LiFePO₄ as the active material will be presented.