Crystallographic engineering to improve the reversible lithium storage capacity of Li2ZnTi3O8 in fast charging batteries

Improving the discharge capacities of anode materials for lithium-ion batteries without sacrificing their cycling stability and rate performance at high current densities is a big challenge due to the limited Li+ diffusion kinetics and electronic conductivity. Therefore, the introduction of dissimilar metal ions into the crystal to form doping defects can effectively improve the microstructure and ion transport kinetics, thus significantly increasing the specific capacity. As an example, a new metal ion-substituted Li2ZnTi3O8 anode material with low agglomeration and high diffusion coefficient performs a large specific capacity of 112.4 mAh g−1 at 7.0 A g−1 and good cycle stability, as well as outstanding rate performance. The obtained electrochemical performance enhancement can be attributed to guest ions changing the microscopic crystal structure, including the influence of dopant atoms on the surrounding bulk atoms and the creation of vacancies, as well as enlarged ion transport tunnels. This strategy provides an effective way to improve the eXtreme Fast Charging of the lithium-ion battery.