Interplanar Spacing Engineering on Copper‐Benzenedicarboxylate Toward Stabilized Lithium Storage

Abstract

Metal–organic frameworks (MOFs) have drawn intensive attention for their prospect as electrode materials of lithium‐ion batteries. However, MOFs with high capacity usually suffer from poor cycling stability, due to the volume fluctuation during cycles. Herein, based on the structure tenability of MOFs, copper phthalate (Cu‐oBDC), copper isophthalate (Cu‐mBDC), and copper terephthalate (Cu‐pBDC) with the same active sites for lithium storage are chosen as target materials and investigated as anodes for LIBs. The three MOF materials display different cycle stability in the galvanostatic charge–discharge test. Cu‐mBDC and Cu‐pBDC show obvious performance attenuation in cycles, while Cu‐oBDC with the largest interplanar spacing (13.02 Å) is eventually stabilized, and the solid electrolyte interface membrane is formed in the later cycling. At a current density of 100 mA g−1, the Cu‐oBDC delivers a reversible specific discharge capacity of 683.6 mAh g−1after 250 cycles, outperforming the other two counterparts. This work adjusts the crystal structure of MOFs toward the improvement of cycle stability and provides a strategy to optimize the electrochemical performances of MOFs.