Copper/carbon coated lithium sodium titanate as advanced anode material for lithium-ion batteries

•Li2Na2Ti6O14 is prepared by a solid state reaction.•Cu/C layer is coated on Li2Na2Ti6O14 by a thermal decomposition.•Cu/C coating layer improves the electrochemical properties of Li2Na2Ti6O14.•Core–shell Li2Na2Ti6O14@Cu/C shows a reversible capacity of 120.3 mAh g−1.

Core–shell Li2Na2Ti6O14@Cu/C is prepared by a preliminary formation of Li2Na2Ti6O14 by solid state reaction and a following coating process with Cu/C layer by thermal decomposition. The amorphous Cu/C coating layer reveals a thickness of 5 nm on the surface of Li2Na2Ti6O14, which improves the electronic conductivity and charge transfer rate of active materials. As a result, Li2Na2Ti6O14@Cu/C shows lower electrochemical polarization and quicker kinetic behavior compared to bare Li2Na2Ti6O14. Cycled at 50 mA g−1, Li2Na2Ti6O14@Cu/C can deliver a reversible capacity of 120.3 mAh g−1 after 50 cycles, which is much higher than the value of 96.8 mAh g−1 obtained by Li2Na2Ti6O14. Even kept at 400 mA g−1, a reversible lithium storage capacity of 76.3 mAh g−1 can be delivered by Li2Na2Ti6O14@Cu/C. The improved electrochemical properties of Li2Na2Ti6O14 are attributed to the electronic conductive Cu/C coating layer on the surface.

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