3 research outputs found
Templated 3D Ultrathin CVD Graphite Networks with Controllable Geometry: Synthesis and Application As Supercapacitor Electrodes
Three-dimensional ultrathin graphitic
foams are grown via chemical
vapor deposition on templated Ni scaffolds, which are electrodeposited
on a close-packed array of polystyrene microspheres. After removal
of the Ni, free-standing foams composed of conjoined hollow ultrathin
graphite spheres are obtained. Control over the pore size and foam
thickness is demonstrated. The graphitic foam is tested as a supercapacitor
electrode, exhibiting electrochemical double-layer capacitance values
that compare well to those obtained with the state-of-the-art 3D graphene
materials
Correlating the Formation Protocols of Solid Electrolyte Interphases with Practical Performance Metrics in Lithium Metal Batteries
The solid electrolyte interphase
(SEI) is regarded as
the most
important and least understood component of lithium metal batteries
(LMBs). Similarly, the connection between SEI formation protocols
and the practical performance metrics in LMBs is even less understood.
Here, we demonstrate the effects of constant current and constant
voltage SEI formation protocols on Coulombic efficiency (CE) and corrosion
losses in LMBs. The formation protocols produce SEIs that reduce parasitic
lithium–electrolyte reactions, improving early cycle CE and
mitigating corrosion of lithium metal. In addition, we establish that
the thicker constant current SEIs formed at low current densities
are better for passivating lithium than constant voltage SEIs, possibly
due to reduced electrolyte permeability in the constant current SEIs.
Using these SEI formation protocols in a high-performing electrolyte,
we improve first-cycle CE by ∼5%, improve compounded CE in
the first 5 cycles by ∼7%, and reduce corrosion-induced CE
losses by ∼8%