Permselective metal-organic framework gel membrane enables long-life cycling of rechargeable organic batteries

Rechargeable organic batteries show great potential as a low-cost, sustainable and mass-producible alternatives to current transition-metal-based cells; however, serious electrode dissolution issues and solubilization of organic redox intermediates (shuttle effect) have plagued the capacity retention and cyclability of these cells. Here we report on the use of a metal-organic framework (MOF) gel membrane as a separator for organic batteries. The homogeneous micropores, intrinsic of the MOF-gel separator, act as permselective channels for targeted organic intermediates, thereby mitigating the shuttling problem without sacrificing power. A battery using a MOF-gel separator and 5,5 '-dimethyl-2,2 '-bis-p-benzoquinone (Me(2)BBQ) as the electrode displays high cycle stability with capacity retention of 82.9% after 2,000 cycles, corresponding to a capacity decay of similar to 0.008% per cycle, with a discharge capacity of similar to 171 mA h g(-1) at a current density of 300 mA g(-1). The molecular and ionic sieving capabilities of MOF-gel separators promise general applicability, as pore size can be tuned to specific organic electrode materials. The use of MOF-gel separators to prevent side reactions of soluble organic redox intermediates could lead to the development of rechargeable organic batteries with high energy density and long cycling life.

Automated summary

The use of MOF gel separators in organic batteries can effectively address electrode dissolution and shuttle effect issues, improving cycle stability and capacity retention. This technology has great potential for various applications, as the pore size can be tailored to specific organic electrode materials.