Surface surgery on TiNb2O7 electrode via N2/Air atmospheric pressure plasma jet for high-rate lithium-ion battery anode

Highlight • Atmospheric Pressure Plasma Jet Technology for the treatment of the electrode. • Defects engineering on the TiNb2O7 ceramics anode materials for the enhancement of electrical conductivity. • Manufacturing N-doped carbon to enhance the high-rate capability. • Enhancement of the electrolyte wettability by modification of the PVdF. • Forming lithium nitride by nitro-groups modification to prevent HF attack. TiNb2O7 (TNO) is regarded as a potential anode material for its high capacity compared to Li4Ti5O12 and high safety due to its adequate Fermi level in lithium-ion batteries. This work represents a promising method of modifying the electrode, which includes polyvinylidene fluoride (PVDF), conductive carbon, and TiNb2O7, using an atmospheric pressure plasma jet (APPj) treatment. Our results reveal that atmospheric pressure plasma jet improves the electrochemical performance by N-doped decoration on conductive carbon, electrolyte wettability enhancement on polyvinylidene fluoride binder, and defects manufacturing in TiNb2O7 anode materials. Good wettability of surface free energy to 44.6 mJ/m2 in the APPj-treated (APP-10) sample contributes to improved cycling performance. Both N-doped carbon and modified TiNb2O7 promote the high-rate capability. The C-rate performance of APP-10 improves by over 200 % at 10C compared to the non-treated sample (APP-0). APP-10 sample also shows 81.9 % retention after 300 cycles at 1C. The formation of Li3N or LiNxOy after cycling due to the nitro-group in the electrode with atmospheric pressure plasma jet offers good protection and high ionic-conductivity interface. This work demonstrates a potential solution to achieve a roll-to-roll modification without any complex synthesis processes, which is a promising technology for the affordable manufacturing of lithium-ion battery.