am9b21702_si_001.pdf (893.01 kB)
Decreasing the Ion Diffusion Pathways for the Intercalation of Multivalent Cations into One-Dimensional TiS2 Nanobelt Arrays
journal contribution
posted on 2020-04-09, 11:34 authored by Casey G. Hawkins, Ankit Verma, Wade Horbinski, Rory Weeks, Partha P. Mukherjee, Luisa Whittaker-BrooksThe
sparse selection of available cathode materials that allow for reversible
intercalation (deintercalation) of Al3+ species represents
a major hurdle in the development of efficient Al-ion batteries. Herein,
we developed cathodes based on TiS2 nanobelts that are
capable of withstanding the high charge density of Al-ion species
with minimal host lattice/ion interactions. The fabricated TiS2 nanobelts are highly anisotropic and are directly grown on
a carbon current collector yielding a spatially controlled array.
The sum of evidence presented in this work indicates that one-dimensional
TiS2 nanobelt arrays can reversibly accommodate an unprecedented
amount of Al ion species within their layered structure with no significant
volume expansion as well as full retention of the nanobelt morphology.
Thus, the one-dimensional morphology, nanoscale dimensions, short
ion diffusion paths, high electrical conductivity, and absence of
additives that hinder ion migration lead to Al-based TiS2 electrochemical devices exhibiting high specific capacity, less
capacity fade, and resilience under higher cycling rates at both room
temperature and elevated temperatures when compared to TiS2 platelets. We also present the effects of sulfur vacancies on the
electrochemical performance of Al-based TiS2–x nanobelt array batteries. Although Al-ion batteries are still
in their infancy, we believe our TiS2 nanobelt array cathode
insertion hosts may play an important role in addressing the poor
kinetics of solid-state Al-ion diffusion to enable efficient alternatives
beyond lithium energy storage devices.