posted on 2024-01-03, 18:05authored byChristian
L. Weindl, Christian E. Fajman, Zhuijun Xu, Tianle Zheng, Gilles E. Möhl, Narendra Chaulagain, Karthik Shankar, Ralph Gilles, Thomas F. Fässler, Peter Müller-Buschbaum
Dendritic copper offers a highly effective method for
synthesizing
porous copper anodes due to its intricate branching structure. This
morphology results in an elevated surface area-to-volume ratio, facilitating
shortened electron pathways during aqueous and electrolyte permeation.
Here, we demonstrate a procedure for a time- and cost-efficient synthesis
routine of fern-like copper microstructures as a host for polymer-templated
Si/Ge/C thin films. Dissolvable Zintl clusters and sol–gel
chemistry are used to synthesize nanoporous coating as the anode.
Cyclic voltammetry (CV) with KOH as the electrolyte is used to estimate
the surface area increase in the dendritic copper current collectors
(CCs). Half cells are assembled and tested with battery-related techniques
such as CV, galvanostatic cycling, and electrochemical impedance spectroscopy,
showing a capacity increase in the dendritic copper cells. Energy-dispersive
X-ray spectroscopy is used to estimate the removal of K in the bulk
after oxidizing the Zintl phase K12Si8Ge9 in the polymer/precursor blend with SiCl4. Furthermore,
scanning electron microscopy images are provided to depict the thin
films after synthesis and track the degradation of the half cells
after cycling, revealing that the morphological degradation through
alloying/dealloying is reduced for the dendritic Cu CC anodes as compared
with the bare reference. Finally, we highlight this time- and cost-efficient
routine for synthesizing this capacity-boosting material for low-mobility
and high-capacity anode coatings.