A nano-truncated Ni/La doped manganese spinel material for high rate performance and long cycle life lithium-ion batteries

The spinel LiMn2O4 cathode material provides high energy and low cost, but suffers from poor cycling performance and rate capability owing to Mn dissolution and Jahn-Teller distortion. Herein, our design concept is to combine Ni-La co-doping with the nanoscale truncated octahedron to solve this issue; namely, a novel nano-LiNi0.08La0.01Mn1.91O4 cathode material with a truncated octahedron is fabricated for the first time through a facile and quick solution combustion approach. It is found that the Ni-La dual doping promotes the {111} surface growth in spinel LiMn2O4, which endows the nano-LiNi0.08La0.01Mn1.91O4 sample with the majority of {111} facets for minimal Mn dissolution and a few truncated {100} facets for rapid Li+ ion migration channels, as well as the nanoscale particles facilitating decreased electronic and ionic diffusion paths. In addition, the introduction of Ni-La elements can strengthen the crystal structure stability and restrain the Jahn-Teller effect effectively. Consequently, the nano-LiNi0.08La0.01Mn1.91O4 presents excellent electrochemical properties with high first discharge capacities of 114.9 and 100.4 mA h g(-1) at 1C and 5C, respectively. Importantly, at the current rate up to 10C, a capacity retention ratio of 89.0% is acquired after an ultra-long 1000 cycles. The CV and EIS measures manifest that the Ni-La dual doping improves the Li+ ion transport rate and weakens the reaction barrier in the nano-LiNi0.08La0.01Mn1.91O4. This research will be a promising candidate for developing long cycle power lithium-ion batteries.

Automated summary

A novel nano-LiNi0.08La0.01Mn1.91O4 cathode material with a truncated octahedron was fabricated through Ni-La co-doping and nanoscale truncated octahedron design. The introduction of Ni-La dual doping promotes the growth of {111} surface in spinel LiMn2O4, reducing Mn dissolution, providing rapid Li+ ion migration channels, and facilitating decreased electronic and ionic diffusion paths. Additionally, Ni-La elements strengthen the crystal structure stability and restrain the Jahn-Teller effect effectively. The nano-LiNi0.08La0.01Mn1.91O4 exhibits excellent electrochemical properties and demonstrates high capacity retention ratio even at high current rates.