Towards Promotion of Graphene/Titania-Based Electrode via Ultrafast and Self-Expansion Reduction for Li-ion Battery

In this study, a facile strategy to promote electrochemical performance of free-standing Li-ion battery electrode composed of titanium dioxide (TiO2) via composite formation with reduced graphene oxide (RGO) using ultrafast and self-expansion reduction reaction (USER) was proposed. This approach induced self-expansion through rapid heating providing abundance of cavities/empty spaces to alleviate volume change during charge/discharge process resulting in boosted storage and conversion response of the system (765 mAh g(-1) at 0.05 A g(-1)) and accelerated Coulombic efficiency. Detailed electrochemical, microscopic and structural analyses (ex-situ) of the film prove that this internal expansion delivers enhanced ionic diffusion and shielding material from volume changes during charge/discharge process. Therefore, we believe that this simple and very fast strategy offers a venue to overcome one of the main bottleneck in promotion of electrochemical performance of other active materials which are sensitive to volume expansion during lithiation/delithiation process.

Automated summary

In this study, a facile strategy using ultrafast and self-expansion reduction reaction (USER) was proposed to improve the electrochemical performance of a free-standing Li-ion battery electrode composed of titanium dioxide (TiO2) by forming a composite with reduced graphene oxide (RGO). The self-expansion induced by rapid heating provided cavities/empty spaces to mitigate volume change during charge/discharge process, resulting in enhanced storage and conversion response of the system (765 mAh g(-1) at 0.05 A g(-1)) and accelerated Coulombic efficiency. Detailed electrochemical, microscopic, and structural analyses demonstrated that this internal expansion improved ionic diffusion and protected the material from volume changes during charge/discharge process. Therefore, this simple and fast strategy offers a solution to enhance the electrochemical performance of other active materials sensitive to volume expansion during lithiation/delithiation process.