LiNb3O8 as a novel anode material for lithium-ion batteries

A novel anode material, LiNb3O8, whose theoretical capacity is 389 mAh/g assuming two-electron transfers (Nb5+ → Nb3+), was prepared by a solid state reaction. It was found that only 3.8 Li per unit formula can be inserted into the as-prepared micro-sized sample. However, when the sample was ball-milled with acetylene black to form a mixed conducting network, 5.4 Li can be inserted in the same voltage range and 2.8 Li (180 mAh/g) can be reversibly extracted after 50 cycles.

► It is the first time to introduce a novel anode material of LiNb3O8 for LIBs.
► The formation of SEI can be avoided because Nb5+/Nb4+ and Nb4+/Nb3+ redox couples are located between 1.0 and 3.0 V.
► A mixed conducting network can be formed when LiNb3O8 was ball-milled with acetylene black.
► 5.4 Li per unit formula can be inserted and 3.3 Li can be extracted into/from the ball-milled sample (LiNb3O8-BM).