One-Step Synthesis of Carbon Nanotubes-Modified and Carbon-Coated Li4Ti5O12 and Its Application to Li Half Cell and LiNi0.8Co0.1Mn0.1O2/Li4Ti5O12 Full Cell

Li4Ti5O12 (LTO) composites modified with carbon nanotubes (CNTs) and carbon coating (LTO@C/CNTs) were synthesized by a simple solid-state reaction. The carbon-coated layers reduce the growth of the primary particles, inhibit interface side reactions and increase electron conductivity, so CNTs-modified LTO can form a conductive network and improve the diffusion path of lithium ions. The LTO@C/CNTs composites show a high-rate capability (150 mAh g(-1) at 10 C, 145 mAh g(-1) at 20 C) with good cycling performance (90.1% and 82.8% capacity retentions after 1000 cycles at 10 C and 20 C, respectively). In addition, superior electrochemical performance is also demonstrated in a full cell with a LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode and LTO@C/CNTs anode (97.1% capacity retentions after 200 cycles at 1 C). The carbon coating and CNTs-modified in LTO can reduce the polarization of potential difference and charge-transfer resistance, improve the diffusion coefficient of lithium ions, and lead to high rate performance and cycle stability.