Reversible intercalation and exfoliation of layered covalent triazine frameworks for enhanced lithium ion storage.

We report that layered covalent triazine frameworks (CTF-1) can be rapidly and reversibly intercalated with either an oxidizing or a non-oxidizing acid based on the acid-base driven mechanism. The obtained CTF-1 intercalated compounds can be readily reacted with nitronium ions and spontaneously exfoliated into 1-2 layered functionalized CTF-1 nanosheets (f-CTF-1) with a high yield of 42%. The f-CTF-1 shows a 2.5 to 3.8 times increase in specific capacitance and much better rate performance when used as an LIB anode.