We present here a one-pot synthetic protocol that yields highperformance silicon-lithium anodes within one hour of reaction time. These anodes consist of silicon nanoparticles that are fully encapsulated by a semi-conducting, porous triazine-based graphdiyne (TzG) polymer that grows directly on the Cu current collector. Cu foil plays three roles in this paradigm-changing method of anode fabrication: it acts (i) as a source of Cu species for a Glaser-type oxidative coupling polymerization, (ii) as templating substrate for the polymer film, and (iii) as the current collector of the electrode. The porous , semi-conducting TzG polymer acts (i) as a strong, flexible binder that envelops Si NPs with a matrix of covalent bonds that can sustain the dramatic volume changes of silicon in repeated de-/lithiation cycles and prevents detrimental abrasion and reformation of the solid electrolyte interface, (ii) as a facilitator of charge transport along its π-conjugated polymer backbone, and (iii) as a medium for mass transport of lithium ions and electrolyte through its microporous channels. The resulting anodes achieve stable electrochemical cycling performance and an extraordinarily high capacity close to the theoretical limit of electrochemical storage using silicon. The reported process uses raw materials and methods common in industrial electrode manufacture and can be transferred and scaled up with ease. Half-cell electrode assemblies in the off-state retain key performance parameters even after thermal stress, and full-cell cycling tests using commercial cathodes demonstrate the viability of this technology in commercial applications.