One-pot synthesis of high-capacity silicon anodes via on-copper growth
of a semi-conducting, porous polymer
Abstract
Silicon-based anodes with lithium ions as charge carriers have the
highest predicted theoretical specific capacity of 3579 mA h
g-1 (for Li15Si4).
Contemporary electrodes do not achieve this theoretical value largely
because conventional production paradigms rely on the mixing of weakly
coordinated components. In this paper, a semi-conductive triazine-based
graphdiyne polymer network is grown around silicon nanoparticles
directly on the current collector, a copper sheet. The porous,
semi-conducting organic framework (i) adheres to the current collector
on which it grows via cooperative van der Waals interactions, (ii) acts
effectively as conductor for electrical charges and binder of silicon
nanoparticles via conjugated, covalent bonds, and (iii) enables
selective transport of electrolyte and Li-ions through pores of defined
size. The resulting anode shows extraordinarily high capacity at the
theoretical limit of fully lithiated silicon. Finally, we combine our
anodes in proof-of-concept battery assemblies using a conventional
layered Ni-rich oxide cathode.