All-Solid-State Lithium Ion Batteries Using Self-Organized TiO2 Nanotubes Grown from Ti-6Al-4V Alloy

Abstract

All-solid-state batteries were fabricated by assembling a layer of self-organized TiO2 nanotubes grown on as anode, a thin-film of polymer as an electrolyte and separator, and a layer of composite LiFePO4 as a cathode. The synthesis of self-organized TiO2 NTs from Ti-6Al-4V alloy was carried out via one-step electrochemical anodization in a fluoride ethylene glycol containing electrolytes. The electrodeposition of the polymer electrolyte onto anatase TiO2 NTs was performed by cyclic voltammetry. The anodized Ti-6Al-4V alloys were characterized by scanning electron microscopy and X-ray diffraction. The electrochemical properties of the anodized Ti-6Al-4V alloys were investigated by cyclic voltammetry and chronopotentiometry techniques. The full-cell shows a high first-cycle Coulombic efficiency of 96.8% with a capacity retention of 97.4% after 50 cycles and delivers a stable discharge capacity of 63 μAh cm−2 μm−1 (119 mAh g−1) at a kinetic rate of C/10.

The Use of Anodic Oxides in Practical and Sustainable Devices for Energy Conversion and Storage

“…The most explored anodic oxide in batteries devices is recently based on TiO 2 applied as anodes in ion batteries to overcome the technical issues during lithiation/delithiation cycling [ 137 , 138 , 139 ]. The major reports are devoted to LIBs [ 27 , 32 , 56 , 140 , 141 ] and sodium-ion batteries (SIBs) [ 28 , 142 , 143 ]. These studies reported the use of nanotubes or nanoporous TiO 2 in pristine form, or doped (with Al, V, Nb, N, S), or in composites (with TiN, SnO 2 , CNT, CuO, CoO, Co 3 O 4 ).…”

“…The search for alternative materials to replace conventional electrodes in LIBs and SIBs aimed to improve kinetic processes and storage capacity [ 59 , 144 ] and extend the device’s life cycle [ 145 , 146 ]. With a theoretical capacity of 330 mAh·g −1 and a good cycle life [ 140 ], the use of nanostructured anodic TiO 2 in LIBs is also stimulated by the low volume change (≈4%) during the reversible intercalation of lithium ions into its structure [ 56 , 83 , 140 , 144 ]. The Li + ions insertion from the cathode into the TiO 2 anode proceed as follows [ 140 ]: TiO 2 + xLi + + xe − → Li x TiO 2 …”

“…With a theoretical capacity of 330 mAh·g −1 and a good cycle life [ 140 ], the use of nanostructured anodic TiO 2 in LIBs is also stimulated by the low volume change (≈4%) during the reversible intercalation of lithium ions into its structure [ 56 , 83 , 140 , 144 ]. The Li + ions insertion from the cathode into the TiO 2 anode proceed as follows [ 140 ]: TiO 2 + xLi + + xe − → Li x TiO 2 …”

“…Besides, especially in the anatase phase, TiO 2 is considered the more electroactive host of Li insertion, with a theoretical electromotive force of 1.7 V (vs. Li/Li + ) [ 27 , 83 , 140 , 145 ]. This low voltage required for lithium insertion improves the battery safety [ 56 ], and prevents the formation of an unstable solid electrolyte interface (dendrites) on the electrode surface, reducing the risk of a short circuit during overload [ 144 ].…”

“…Sugiawati et al [ 140 ], for instance, used anodized TiO 2 -NT to build an all-solid-state LIB consisting of a TiO 2 -NT anode covered with a thin layer of polymer electrolyte (MMA-PEG) as electrolyte and separator; and a layer of LiFePO 4 as a cathode. This system obtained high-capacity retention of 97.35% and Coulombic efficiency of 96.78% after 50 cycles.…”