Complex titanates Sr1-xPbxLi2Ti6O14 (0≤x≤1) as anode materials for high-performance lithium-ion batteries. (10th September 2016) - Qian, Shangshu
Graphical abstract: Highlights: Sr1-x Pbx Li2 Ti6 O14 (0≤x≤1) is prepared by a simple solid state reaction. Sr0.5 Pb0.5 Li2 Ti6 O14 exhibits enhanced lithium storage capability. Sr0.5 Pb0.5 Li2 Ti6 O14 can deliver a capacity of 141.8 mAh g −1 at 700 mA g −1 . In-situ XRD is performed to study the reversibility of Sr1-x Pbx Li2 Ti6 O14 . Abstract: With the Pb doping content at Sr-site increasing, a series of Sr1-x Pbx Li2 Ti6 O14 (x = 0, 0.25, 0.50, 0.75, 1.0) are synthesized by a simple solid-state reaction. It is found that the reversible capacity and rate capability experience a parabolic course from SrLi2 Ti6 O14 to PbLi2 Ti6 O14 . Among all the as-prepared samples, Sr0.5 Pb0.5 Li2 Ti6 O14 shows the best cycling and rate properties. It delivers an initial charge capacity of 163.2 mAh g −1 at 100 mA g −1 with the capacity retention of 96.08% after 100 cycles. In addition, it can also deliver a reversible capacity of 141.8 mAh g −1 at 700 mA g −1 . The superior electrochemical properties of Sr0.5 Pb0.5 Li2 Ti6 O14 are attributed to the reduced charge transfer resistance and increased lithium-ion diffusion coefficient after doping. Besides, in-situ X-ray diffraction is also performed to investigate the lithium-ion insertion/extraction behaviors of SrLi2 Ti6 O14, Sr0.5 Pb0.5 Li2 Ti6 O14 and PbLi2 Ti6 O14 . The observed results confirm that Sr0.5 Pb0.5 Li2 Ti6 O14 has good structural stability and reversibility for repeated lithium storage.