Abstract
Journal of the Electrochemical Society 2019, 166, A3182-A3188
Composite Electrode Ink Formulation for All Solid-State Batteries
Shen FY, Dixit MB, Zaman W, Hortance N, Rogers B, Hatzell KB
Solid-state batteries employ composite electrodes which contain a solid
ion conductor, a solid active material, a conductive additive, and a
binder. The electrode microstructure fundamentally differs from
electrodes in conventional batteries because the pore region is ion
blocking. While there is extensive research on how to integrate a
lithium metal with inorganic electrolytes, there is less knowledge on
how an electrode can be integrated with an inorganic electrolyte.
Solution processing techniques are ideal for scalable manufacturing and
rely on creating an ink which combines the solid material, a binder, and
solvent. Ink engineering relies on tailoring the fluidics (rheology),
aggregation behavior, and stability for a desired coating process. In
this work, we systematically probe the role of two ink constituents: the
(1) binder, and (2) solvent on electrode microstructure formation.
Lithium titanate anodes achieve nearly a 3-4X increase in capacity from
1.5 mAh/g and 3 mAh/g to 9 mAh/g and ?12 mAh/g when a high viscosity
solvent is employed. The binder plays a larger role in dictating
performance of the electrode than surface adhesion properties. Inks with
well dispersed constituents led to more effective electrodes for charge
storage.