Free-Standing Li4Ti5O12/Carbon Nanotube Electrodes for Flexible Lithium-Ion Batteries

Abstract

Lithium-ion batteries (LIBs) have been used in many fields, such as consumer electronics and automotive and grid storage, and its applications continue to expand. Several studies have attempted to improve the performance of LIBs. In particular, the use of high-capacity silicon and tin as anodes has been widely studied. Although anodes composed of silicone and tin have high theoretical capacities, poor electrical conductivity and considerable volume expansion of such anodes deteriorate the LIB performance. Thus, Li4Ti5O12 (LTO), a zero-strain material, has attracted much attention with high cycle stability and rate capability through improved electrical conductivity. However, LTO has the disadvantages of a low electrical conductivity (10−8 to 10−13 S cm−1) and moderate Li+ ion diffusion coefficient (10−9 to 10−16 cm2 s−1). In this study, the flexible and free-standing composite films were fabricated using only LTO and multi-walled carbon nanotube(CNT) with high electrical conductivity and ion diffusivity. The prepared LTO/CNT films showed a higher charge/discharge capacity than the theoretical capacity of the LTO electrode.

Enhanced LiMn2O4 cathode performance in lithium-ion batteries through synergistic cation and anion substitution

“…The inclined line at low frequencies is described as a Warburg-type element, reflecting the solid-state diffusion of Li into the bulk of the active materials. 29,59,61 These are designated as the solid electrolyte interface impedance (R f ) and charge-transfer impedance (R ct ), which are typically associated with the electronic conductivity of the materials. 15,62 Fig.…”

Flexible Solid-State Lithium-Ion Batteries: Materials and Structures

“…It should be emphasized that carbon nanotubes have applications in rigid batteries. In flexible batteries, in addition to enhancing electron transfer and increasing surface area, the inherent flexibility of carbon nanotubes also plays a role [32,33]. In addition, doping carbon nanotubes with active materials is another standard method to improve the performance of flexible electrodes [26][27][28][29][30][31][32][33][34].…”

CNT Sheets Co‐Loaded with Sulfur and Silicon Oxides: Free Standing Anodes for Lithium and Sodium‐Ion Batteries

“…[10] To enhance the electrochemical application of CNT sheets as anodes for SIB/LIB, composite formation with various high capacity materials (Sn, Si, SiO x , Sn 4 P 3 , Sb, SiN/Si/SiN, Co/Ni silicate, Fe@Si@SiO 2 , Li 4 Ti 5 O 12 , red P@N doped graphene) has been explored. [11][12][13][14][15][16][17][18][19][20][21] Silicon based anodes for LIB has gained prominence in recent years and electrochemical properties of Si, SiO, SiO 2 and SiO x compounds have been reported. [22] Among these, Si has the highest theoretical specific capacity of 4200 mAh g À 1 but exhibits poor cyclability due to the massive volume alteration (~300 %) during lithiation/de-lithiation process.…”

“…This is due to fact that in CNT sheets the properties are controlled by weak van der Waal interactions unlike the strong sp 2 C−C bonding in case of CNTs [10] . To enhance the electrochemical application of CNT sheets as anodes for SIB/LIB, composite formation with various high capacity materials (Sn, Si, SiO x , Sn 4 P 3 , Sb, SiN/Si/SiN, Co/Ni silicate, Fe@Si@SiO 2 , Li 4 Ti 5 O 12 , red P@N doped graphene) has been explored [11–21] . Silicon based anodes for LIB has gained prominence in recent years and electrochemical properties of Si, SiO, SiO 2 and SiO x compounds have been reported [22] .…”