In Situ TEM Observation of the Electrochemical Process of Individual CeO₂/Graphene Anode for Lithium Ion Battery

Abstract

The reaction mechanism of ceria as an anode in a lithium ion battery (LIB) is unknown. To solve this issue, a nano-LIB was constructed inside a transmission electron microscope (TEM) using an individual CeO 2 /graphene composite as the anode. The lithiation/delithiation cycles of the CeO 2 /graphene composite were conducted inside the TEM, and the electrochemical process was in situ monitored by simultaneous determination of the microstructure with high-resolution TEM, electron diffraction, and electron energy loss spectroscopy. The surfaces of the graphene nanosheets and ceria nanoparticles were covered by a nanocrystalline Li 2 O layer after lithiation, and the Li 2 O layer shrank and showed partially reversible changes after delithiation. The CeO 2 nanoparticles showed imperceptible volumetric and morphological changes, while comprehensive analysis revealed a fully reversible phase transformation between fluorite CeO 2 and cubic Ce 2 O 3 during the electrochemical process. These results give direct evidence and profound insights into the lithiation/delithiation mechanism of CeO 2 /graphene anode in a LIB.

Ultrathin Conductive CeO2Coating for Significant Improvement in Electrochemical Performance of LiMn1.5Ni0.5O4Cathode Materials

“…• C followed by four weeks at room temperature (25 • C), while the other set of samples was placed in the electrolyte for five weeks at room temperature. After five weeks, the electrolyte was sent for inductively coupled plasma-mass spectroscopy (ICP-MS) analysis to determine the amount of Mn dissolution.…”

“…25,26 Other studies have included the use of CeO 2 as a surface protective layer to improve the cycleability and capacity retention of LiCo 1/3 Ni 1/3 Mn 1/3 O 2 , LiFePO 4 , and LiCoO 2 , when used as cathode materials.…”

Synthesis of 3D porous CeO2/reduced graphene oxide xerogel composite and low level detection of H2O2

“…The carbon material can form a homogeneous matrix which will enhance the electronic conductivity and act as a buffer to accommodate the volume change in the inorganic metal oxides. Among the metal oxide nanoparticles, only a very few researchers investigated electrochemical properties of CeO 2 [4,[13][14][15][16]. Furthermore, some of the interesting properties like electrocatalytic, high surface area, non-toxicity, biocompatibility, oxygen storage capacity, chemical stability and high electron transfer capability make CeO 2 a promising material for electrochemical sensor [17][18][19][20][21][22].…”

Hierarchical structured graphene/metal oxide/porous carbon composites as anode materials for lithium-ion batteries

“…, much higher than that of mC-CeO2 (~360 mA h g -1 ) or m-CeO2 (~110 mA h g -1 ), and any other previous reports [10][11][12]. G-mC-CeO2 also has the best rate capability among these three samples (Fig.…”

“…But the severe volume change and poor electronic conductivity of Co3O4 during the charge and discharge processes may reduce its cycle and rate performances [8,9]. Recently, CeO2 is reported as a novel LIB anode material and displays opposite electrochemical properties such as low theoretical capacity but imperceptible volumetric and morphological changes because of a fully reversible phase transformation between fluorite CeO2 and cubic Ce2O3 during the electrochemical process [10][11][12]. In addition, the intrinsic low electronic conductivity of CeO2 is also an impediment to its practical use for LIBs.…”