Metal chelation based supramolecular self-assembly enables a high-performance organic anode for lithium ion batteries

The rising pursuit for green rechargeable energy storage devices desires novel electrode materials with cost-effective, environmental-friendly properties besides high electrochemical performance, boosting the rapid development of organic electrodes. However, the organic electrode materials in most reports can hardly be used in the real applications due to relatively poor electrochemical performance. Herein, by utilizing a smart supramolecular self-assembly between metal ions and ligands, we facilely chelate the rhodizonic acid disodium salt (RA) using ferric ions and generate a novel organic anode material (RAFe) for the first time. The strong chelation interaction between ferric ions and rhodizonic acid changes its initial structure and characteristics, enabling the obtained organic RAFe compound with outstanding electrochemical performance as anode for lithium ion batteries (LIB), which includes high reversible capacity (1283 mAh/g at 0.1A/g), excellent rate capability, long cycling stability (0.5 A/g over 300 cycles with a capacity retention of 90.76%, i.e. 0.03% decay per cycle). Even at a high mass loading of 4.0 mg/cm, this organic anode can still deliver a capacity over 1000 mAh/g with the specific area capacity of 4.09 mAh/cm at 0.2 A/g, and maintains it over 92.4% after 100 cycles. Apart from offering a promising organic anode material, this work also broadens the application of metal chelation interaction based supramolecular self-assembly in energy storage territory which will inspire the preparation of other high-performance organic materials for advanced LIBs.