One-step synthesis of SnO_x nanocrystalline aggregates encapsulated by amorphous TiO₂ as an anode in Li-ion battery

Abstract

SnO x nanocrystalline aggregates (NAs) encapsulated by an amorphous TiO 2 layer have been successfully designed by a one-step flame spray pyrolysis (FSP). The synthesized SnO x NAs@TiO 2 with different degrees of aggregations were composed of SnO x nanocrystallites ranging from 5 nm to 10 nm and a TiO 2 layer with a thickness of 1-5 nm. The encapsulated TiO 2 layer was introduced in situ by incorporating TiCl 4 into the downstream of an FSP reactor, where TiO 2 nucleated and grew in the surface of the SnO x NAs. The hydrolysis temperature of TiCl 4 in a flame was controlled to synthesize amorphous TiO 2 with intrinsic electrochemical features. As an anode in LIBs (Li-ion batteries), the SnO x NAs@TiO 2 electrode showed superior cycle life and rate performance (capacity of 350 mA h g À1 after 300 cycles and 332 mA h g À1 at 1 A g À1 ) compared to pure SnO x or TiO 2 electrodes. The remarkably enhanced Li + storage performance is mainly attributed to the nanoscale of nanocrystalline aggregates, the core-shell structure of SnO x @TiO 2 and the amorphous state of TiO 2 . † Electronic supplementary information (ESI) available: Schematic diagram of FSP equipment. TEM, particle size distribution, TGA, BET of as-prepared SnO x NAs@TiO 2 . Coulombic efficiency of SnO x NAs@TiO 2 electrode. TEM and SEM images of SnO x and TiO 2 NAs. See

Rapid flame synthesis of internal Mo6+ doped TiO2 nanocrystals in situ decorated with highly dispersed MoO3 clusters for lithium ion storage

“…Moreover, the first scan on the negative-current side have a broad reduction peak in the range of 0 to 1.25 V. Compared with the following scans, these irreversible peaks are mainly attributed to the formed solid electrolyte interphase (SEI) films. 20,21,36 These observed peaks further confirmed that the electrochemical reaction takes place in a multistage process with active TiO 2 and MoO 3 components. Fig.…”

“…21,31 These components were mixed and stirred into slurry with N-methyl-2pyrrolidone (NMP) and uniformly pasted on Cu foils (19 µm) with a membrane thickness of 50 µm. The average loading mass of active materials have an average value of 0.52 mg/cm 2 (the area of used Cu foils is 1.44 cm 2 ).…”

“…Recently, oxides nanocrystals with high electrochemical acitivity (i.e., SnO 2 : ~ 790 mA h g -1 , MoO 3 : ~ 1111 mA h g -1 ) have coupled with stable TiO 2 for achieving superior performance. [20][21][22] Yu et al have demonstrated that 5 at.% Sn modified TiO 2 nanotube exhibited a highly specific capacity of 386 mA h g -1 at 0.1 C after 50 cycles. 23 Similar stable capacity of 485 mA h g -1 at 50 mA g -1 is delivered for SnO 2 /TiO 2 .…”

Intermetallic Ni3Sn4-based graphene@carbon hybrid composites for lithium-ion batteries

“…In a typical yolk‐shell structure, surface of the shell structure forms a stable solid electrolyte interface while the yolk part of the structure shrinks and expands without forming a solid electrolyte interface. Moreover, even if the active electrode material as the yolk structure pulverizes during the intercalation processes, the components will be kept within the structure and will continue to provide electrical contact …”

“…Moreover, even if the active electrode material as the yolk structure pulverizes during the intercalation processes, the components will be kept within the structure and will continue to provide electrical contact. [9][10][11][12][13][14][15][16] Several research studies have proposed a very thin layer of carbon over the surface of active electrode materials by using hydrocarbons such as glucose, and these approaches have been successfully applied to various electrode materials in the field of Li-ion batteries. However, thin carbon layers over the active electrode materials could accommodate the mechanical stresses in a limited extent because the layer disintegrates in each cycle if the core electrode suffers severely from large volumetric changes.…”