Silicon-based anodes with lithium ions as charge
carriers have the highest predicted charge density of 3579 mA h g<sup>-1</sup>
(for Li<sub>15</sub>Si<sub>4</sub>) while being comparatively safe. Contemporary
electrodes do not achieve these theoretical values largely because production
paradigms remained unchanged since their inception and rely on the mixing of
weakly coordinated, multiple components. In this paper, we present the one-pot
synthesis of high-performance anodes that reach the theoretical capacity of the
fully lithiated state of silicon. Here, a semi-conductive triazine-based graphdiyne polymer network is grown around silicon nanoparticles
directly on the current collector, a copper sheet. The current collector (Cu)
acts as the catalyst for the formation of a semi-conductive triazine-based graphdiyne
polymer network that grows around the inorganic, active material (Si). In
comparison to established electrode assemblies, this process (i) omits any
steps related to curing, drying, and annealing, (ii) does away with binders and
conductivity-enhancing additives that decrease volumetric and gravimetric capacity,
and (iii) cancels out the detrimental effects on performance, chemical and
physical stability of conventional, three-component anodes (Si, binder, carbon
black). This is because, the porous, semi-conducting organic framework (i) adheres
to the current collector on which it grows <i>via</i> cooperative van der Waals
interactions, (ii) acts effectively as conductor for electrical charges and
binder of silicon nanoparticles <i>via</i> conjugated, covalent bonds, and (iii)
enables selective transport of mass and charge-carriers (electrolyte and
Li-ions) through pores of defined size. As a result, the anode shows
extraordinarily high capacity at the theoretical limit of fully lithiated
silicon, excellent performances in terms of cycling (exceeding 70% capacity
retention after 100 cycles), and high mechanical and thermal stability. These high-performance
anodes pave the way for
use in flexible,
wearable electronics and in environmentally demanding applications.
Scalable one-pot synthesis of bismuth sulfide nanorods as an electrode active material for energy storage applications
