Abstract:

The negative electrode active material of decommissioned lithium-ion batteries is mainly graphite.At present,the treatment methods for graphite in decommissioned lithium-ion batteries are mainly landfills,and it causes resources waste and environmental pollution.Existing research shows that graphite in decommissioned lithium-ion batteries can be purified and regenerated by methods such as high temperature pyrolysis and acid leaching.Using the recycled graphite to modify cement-based composite materials,the mechanical and electrical properties could be improved.Results showed that introduc-tion of recycled graphite can enhance the compressive and flexural properties of the material,and the maximum increase was 57.3% and 84.4% respectively.In addition,the introduction of recycled graphite effectively reduced the resistivity and polarization time of the material.When the additive amount of recycled graphite was 3%,the resistivity of the material after curing for 28 d was only 249 Ω·cm.The composite material also had typical pressure-sensitive characteristics.The composite material prepared in this study are expected to be used for real-time dynamic monitoring of concrete structures.In addition,it is of great significance for the recycling of all components of waste lithium-ion batteries and the development of functional cement materials.

Key words: recycled graphite, cement based composite, decommissioned lithium-ion batteries