Mitigating interfacial reactions in Li4Ti5O12 anodes through carbon shells synthesized by spray granulation

Abstract

Recently, Li₄Ti₅O₁₂ has emerged as a potential alternative to graphite for automotive battery anodes. However, gas production in LTO batteries, which results in battery expansion, is a significant concern. This study employed sucrose as the carbon source. The methodology involved coating sucrose onto LTO through spray granulation, followed by reduction to create a uniform carbon layer of 2–3 nm thickness onto the LTO surface. Analysis of the material properties and electrochemical behavior demonstrated that a more stable solid electrolyte interphase (SEI) layer was formed on the surface of the LTO@C samples. This robust SEI layer functioned as the most effective barrier and enhanced the Li-ion diffusion coefficient. Cells fabricated with LTO@C sucrose 5% electrodes exhibited exceptional capacity retention (∼97%) and a specific discharge capacity of 161 mAh g⁻¹ after 200 cycles at 1C in a 1–2 V voltage range. Furthermore, linear sweep voltammetry (LSV) measurements revealed a higher overpotential for the hydrogen evolution reaction at ∼2.25 V (Li/Li⁺), indicating that the surface activity of LTO was successfully regulated. Our results show that spray granulation can not only quickly and effectively coat uniformly but also efficiently suppress gas production, thus enhancing the potential of LTO@C as an automotive battery anode material.