Fabrication of SiO2 nanofiber-integrated all-inorganic electrodes for safer Li-ion batteries

Abstract

Energy density, rate capability, and safety are often compromised in lithium-ion batteries (LIBs). To overcome this dilemma, novel electrode structure design is considered as one of the most promising routes. However, simple and scalable fabrication methods are currently very limited. Here, an electrostatic self-assembled three-dimensional Li4Ti5O[Formula: see text] (3D-LTO) electrode with high-energy density as a whole and excellent thermal stability was fabricated by regulating the zeta potential of electrode components. Such a 3D electrode features an intergraded current collector layer of SiO2/ketjen black (KB) and active material layer of SiO2/KB/LTO/carbon fiber (CF). Benefiting from its well-designed electronic conductive 3D skeleton and desirable chemical affinity with the liquid electrolyte, outstanding cyclability (capacity retention of 85% over 80 cycles) and rate capability (125 mAh g[Formula: see text] at 5 C) could be achieved for Li/3D-LTO cells with a high LTO mass loading of 10 mg cm[Formula: see text]. Excellent thermal-tolerance of the 3D electrode enables the cell with good operability and safety at an elevated temperature of 80[Formula: see text]C. The discharge capacity of the Li/3D-LTO half-cell remains 160 mAh g[Formula: see text] at 1 C after 100 cycles. This simple and scalable method for the fabrication of the 3D electrodes boosts the energy density, rate capability, and high-temperature operability, which is promising for next-generation LIBs.