Ultra-Thin Hydrogen-Organic-Framework (Hof) Nanosheets for Ultra-Stable Alkali Ions Battery Storage

Fully organic frameworks-based batteries with excellent physicochemical stability and long-term high capacity, will definitely reduce the cost, carbon emission, and metal consumption and contamination. Herein, we developed an ultra-stable and ultra-thin perylene-dicyandiamide-based hydrogen organic framework (HOF) nanosheet (P-DCD) of around 3.5 nm in thickness. When applied in cathode, P-DCD material exhibited exceptional long-term capacity retainment for alkali-ion batteries (AIBs). Strikingly for lithium-ion batteries (LIBs), at a current of 2 A g-1 the large reversible capacity of 108 mA h g−1 showed no attenuation within 5,000 cycles. For sodium-ion batteries (SIBs), the related capacity retained 91.7% within 10,000 cycles compared with the initial state, significantly much more stable than conventional organic materials reported previously. Mechanism studies through ex-situ and in-situ experiments and theoretical DFT calculation revealed that the impressive long-term performance retention originated from the large electron delocalization, fast ion diffusion, and physicochemical stability within ultra-thin two-dimensional (2D) of P-DCD, featuring π-π and hydrogen bonding stacking, nitrogen-rich units and low impedance. The advantageous features demonstrate that rationally designed stable and effective organic frameworks will pave the way to utilize complete organic materials toward developing next-generation low-cost and highly stable energy storage batteries.