Growth and growth mechanism of oxide nanocrystals on electrochemically exfoliated graphene for lithium storage

Abstract

Difficulty of growing metal oxides on intrinsic graphene due to few defects and functional groups on its surface was overcome by deposition of polymerized precursors via multiple interacting sites, followed by crystallization of metal oxides inside the aggregated polymer. As a typical example, Mn 3 O 4-decorated electrochemically exfoliated graphene (EEG) was successfully prepared and served as an advanced anode material for lithium-ion batteries. Because EEG possesses higher electronic conductivity and stronger mechanical strength in comparison with commonly used reduced graphene oxide (rGO), the new composite of EEG-Mn 3 O 4 exhibits much better electrochemical performance than rGO-Mn 3 O 4 , including superior reversible capacity and better cycling stability.

Synthesis of Highly Stable LTO/rGO/SnO2 Nanocomposite via In Situ Electrostatic Self‐Assembly for High‐performance Lithium‐Ion Batteries

“…[43] The O1s peak (Figure 3d) is subdivided into three peaks of 530.1, 531.9, and 533.2 eV, corresponding to TiOC, SnOC, and TiOSn bonds, indicating that LTO, rGO, and LTO are connected by the TiOC, SnOC, and TiOSn bonds. [44][45][46][47] Further observation reveals 3D conductive network rGO acted as a bridge to connect LTO (internally) and SnO 2 (externally) to promote the formation of LTO/rGO/SnO 2 nanocomposite (see Figure 3c,d). At the same time, rGO provides a good channel for Sn ions to be doped onto LTO lattice, improving the structural stability and charge transport ability of LTO.…”

Highly responsive screen-printed asymmetric pressure sensor based on laser-induced graphene

“…Generally, the preparation technologies of graphene are mainly separated into two types, namely topdown and bottom-up approaches. Top-down process generally breaks the van der Waals force between stacked layers of graphite and obtains graphene sheets after dispersion, which mainly includes mechanical exfoliation [18], chemical oxidation [19], electrochemical intercalation [20] and so on. And bottom-up technique usually involves the polymerization and rearrangement of carbon atoms or clusters of small molecules through high temperature activation to form mono-to multilayer graphene, such as chemical/physical vapor deposition (CVD/PVD) [21,22], epitaxial growth [23], laser direct synthesis [24], etc.…”

Graphene-Based Mesoporous SnO2 Nanosheets as Multifunctional Hosts for High-Performance Lithium–Sulfur Batteries

“…The increasing demand for portable electronic devices, electrical vehicles, and other emerging energy storage systems has triggered the research development and production of rechargeable batteries. − As one of the popular rechargeable batteries, lithium-ion batteries (LIBs) using LiCoO 2 or LiFePO 4 cathode and graphite anode have not been able to satisfy this demand in terms of their low energy densities (∼200 Wh kg –1 ). In recent decades, lithium–sulfur (Li–S) batteries have attracted a great deal of attention because of their high theoretical energy density (2600 Wh kg –1 ). − In addition to the superior theoretical capacity of sulfur (1675 mAh g –1 ) as cathode material, elemental sulfur has several other advantages such as low cost, natural abundance, and environmental benignity. − However, commercial implementation of Li–S batteries has been hindered by a series of obstacles: (1) ultralow electronic conductivities of elemental sulfur (S 8 , 5 × 10 –30 S cm –1 ) and its discharge product (Li 2 S 2 and Li 2 S) lead to slow kinetics reaction and low utilization of sulfur; (2) large volumetric expansion of sulfur upon lithiation (80%) makes the cathode structure unstable and thereby deteriorates the cycle performance; (3) the lithium polysulfide intermediates (Li 2 S x , 4 ≤ x ≤ 8) can dissolve into the organic electrolyte and migrate to the anode side.…”