individual particles of increased size can be discerned that correspond to lithiated and volumetrically expanded domains of LixSi all embedded in a fabric of polymer and SEI (ii). After the first delithiation, the size of the spherical Si domains decreases (iii), and after the 100 th delithiation, all that can be said is that the TzG/Si composite shows no discernible large cracks or deformations (iv) (Figure and). A comprehensive discussion of these findings is presented in Supplementary Information section S2.2. For now, we conclude that: (i) the alloying reaction between lithium and Si NPs takes place unhindered, hence, the TzG polymer matrix allows lithium to diffuse, (ii) the conductivity enhancing additive in TzG/Si/CB@Cu has no positive effect on the performance of TzGbased electrodes, hence, the initial, modest conductivity of undoped TzG is no impediment for its use in electrodes; and (iii) the TzG polymer does not participate in the detrimental depletion of lithium or electrolyte on its own, and SEI formation occurs exclusively in the presence of Si NPs. It is particularly surprising that TzG-based electrodes perform as well as they do, given their low conductivity in the pristine, unlithiated state. While an in-depth study of the electric conductivity of lithiated TzG/Si@Cu is out of the scope of this work, XPS results for TzG@Cu suggest that the Potential vs. specific capacity curves for consecutive de-/lithiation cycles. Full-cell performance data for an assembly consisting of a TzG/Si@Cu anode paired with a NCM811 cathode. The n/p ratio is 0.94 (NCM811 loading of 6.502 mg cm -1 and Si loading of 0.291 mg cm -2 ). The full-cell was precycled at C/14 (based on the Si mass-loading) for two initial cycles, and at C/8 for all subsequent cycles, within a potential window of 4.2-1.8 V. c, Specific capacities normalized to Si mass / CE vs. cycle number and d, charge-discharge curves.