A new application of oily cold rolling mill sludge for preparing Fe 2 O 3 /graphene as anodes for lithium-ion batteries

Oily cold rolling mill sludge, which consists of iron and oil and is hard to degrade, may cause problems in air or soil pollution. Therefore, the effective use of oily cold rolling mill sludge can not only reduce pollution but also produce environmental and economic benefits. In this research, the sludge was first used as the precursor to prepare LIB materials. As an anode material for lithium ion batteries, it showed a large reversible capacity of 560 mA h g −1 after 100 cycles at a small charge–discharge rate current of 100 mA g −1 as well as good rate capabilities of 508 and 380 mA h g −1 at ultrahigh current densities of 2000 and 5000 mA g −1 .