Yttrium-doped Li4Ti5O12 nanoparticles as anode for high-rate and high-energy lithium-ion batteries

Li4Ti5O12 (LTO) batteries are known for safety and long lifespan due to zero-strain and stable lattice. However, their low specific capacity and lithium-ion diffusion limit practical use. This study explored modifying LTO through yttrium doping by hydrothermal method to form Li4Y0.2Ti4.8O12 nanoparticles. This approach optimized electron and ion transport, markedly enhancing rate and cycle performance. XRD and TEM revealed that Y addition increased interplanar distance of LTO and widened Li+ transport pathways. XPS indicated that Y doping augmented the oxygen vacancy concentration and Ti3+ content. UV tests demonstrated a band gap reduction from 3.72 eV to 2.94 eV, accompanied by enhanced electronic conductivity. EIS tests showed lithium-ion diffusion coefficient remarkably increased to 1.27 x 10(-10) cm(2) s(-1). The initial discharge capacity of Li4Y0.2Ti4.8O12 at 1 A g(-1 )reached 198.9 mAh g(-1) and retained 89.3% capacity after 1000 cycles. At 6 A g(-1), the discharge capacity was 161.1 mAh g(-1), while at an ultra-high current density of 20 A g(-1), it reached 78.8 mAh g(-1), highlighting its robust rate performance. The yttrium-doped and nano-morphology stabilizes the LTO lattice, enhancing rate performance and cycling stability. This study reveals that LTO has the potential to be used in the high-energy fast-charging storage market.