The recycling of expired aminocaproic acid injection for mint-leaf-like zinc aminocaproate

In this work, a zinc (Zn) aminocaproate complex was extracted from expired aminocaproic acid injection by way of one-step facile chemical liquid-phase deposition for the first time, and the morphology, microstructure and electrochemical lithium (Li)-storage performances were also investigated. The results showed that the obtained zinc aminocaproate complex displayed a uniform mint-leaf-like flower morphology with a particle size of 300–500 nm. The reversible discharge specific capacities were 379.1 mAh/g at 100 mA/g and 100.6 mAh/g at 2000 mA/g, indicating high electrochemical lithium-storage performances. Conversion reaction and alloying/dealloying were confirmed to take part in the electrochemical lithium-storage mechanism. Seemingly, orderly hierarchical mint-leaf-like morphology may play an important role in improving the electrochemical lithium-storage capacity of the zinc aminocaproate complex anode. The satisfactory results may open a new path to develop the circular economy of expired waste aminocaproic acid injection which is very important for the environmental protection and sustainable development.