Alumina-coated and manganese monoxide embedded 3D carbon derived from avocado as high-performance anode for lithium-ion batteries

Derived from avocado fruit, a three dimension (3D) carbon is prepared via a hydrothermal/pyrolysis process followed by embedding with MnO nanoparticles by a wet chemical method and coating with Al ₂ O ₃ through an atomic layer deposition technique. The obtained material presents a hierarchical structure that MnO nanocrystals wrapped in 3D carbon and then encapsulated in a uniform Al ₂ O ₃ layer with a thickness of about 5 nm. Benefiting from this hierarchical structure in which 3D carbon offers numerous electronic pathways to enhance the conductivity and Al ₂ O ₃ nanolayer provide a shelter to keep away from dissolution of Mn ⁴⁺ and volume changes during charge/discharge process. This material (marked as C/MnO@Al ₂ O ₃ ) has exhibited high rate performance and excellent cyclability as an anode for lithium ion batteries. A high specific capacity of about 600 mA h g ⁻¹ is achieved at a current density of 1000 mA g ⁻¹ and the electrode can still deliver a high specific capacity of about 1165 mA h g ⁻¹ at 150 mA g ⁻¹ after 100 cycles. These results facilitate a green and high potential of anode materials towards promising devices for advance performance of lithium-ion batteries.