Hybrid Anodes of Lithium Titanium Oxide and Carbon Onions for Lithium-Ion and Sodium-Ion Energy Storage

This study demonstrates the hybridization of Li4Ti5O12(LTO) with different types of carbon onions synthesized from nanodiamonds. The carbon onions mixed with a Li(4)Ti(5)O(x)precursor for sol-gel synthesis. These hybrid materials are tested as anodes for both lithium-ion battery (LIB) and sodium-ion battery (SIB). Electrochemical characterization for LIB application is carried out using 1 mLiPF(6)in a 1:1 (by volume) ethylene carbonate and dimethyl carbonate as the electrolyte. For lithium-ion intercalation, LTO hybridized with carbon onions from the inert-gas route achieves an excellent electrochemical performance of 188 mAh g(-1)at 10 mA g(-1), which maintains 100 mAh g(-1)at 1 A g(-1)and has a cycling stability of 96% of initial capacity after 400 cycles, thereby outperforming both neat LTO and LTO with onions obtained via vacuum treatment. The performance of the best-performing hybrid material (LTO with carbon onions from argon annealing) in an SIB is tested, using 1 mNaClO(4)in ethylene/dimethyl/fluoroethylene carbonate (19:19:2 by mass) as the electrolyte. A maximum capacity of 102 mAh g(-1)for the SIB system is obtained, with a capacity retention of 96% after 500 cycles.