High Volumetric Energy and Power Density Battery Anodes via Graphene Functionalization

NU 2020-186

INVENTORS
Jin-Myoung Lim
Mark Hersam*

ABSTRACT
The realization of lithium-ion battery anodes with high volumetric energy but without Li dendrite formation at high rates remains a key challenge for emerging technologies including electric vehicles and grid-level energy storage. Although anode materials with high operating potentials such as lithium titanate have been substantially studied to avoid Li plating at high rates, this approach compromises energy density due to the reduced voltage window. This invention presents graphene-coated Li₂TiSiO₅(G-LTSO) as a high volumetric energy and power density anode for lithium-ion batteries. G-LTSO forms a highly-packed electrode structure with electronically and ionically conductive networks to deliver superior electrochemical performance. The graphene coating yields minimal structural changes and reduced amorphization compared to pristine LTSO, resulting in high cycling stability. Furthermore, G-LTSO exhibits not only high charge and discharge capacities but also low over potentials at high rates with minimal voltage fading due to low charge-transfer resistances and reduced formation of solid-electrolyte interphase. The combination of highly-compacted electrode morphology, stable high-rate electrochemistry, and low operating potential enables G-LTSO to achieve exceptional volumetric energy and power densities that overcome incumbent challenges for lithium-ion batteries.

APPLICATIONS