Hollow Iron Oxide Nanoparticles for Application in Lithium Ion Batteries

Abstract

Material design in terms of their morphologies other than solid nanoparticles can lead to more advanced properties. At the example of iron oxide, we explored the electrochemical properties of hollow nanoparticles with an application as a cathode and anode. Such nanoparticles contain very high concentration of cation vacancies that can be efficiently utilized for reversible Li ion intercalation without structural change. Cycling in high voltage range results in high capacity (∼132 mAh/g at 2.5 V), 99.7% Coulombic efficiency, superior rate performance (133 mAh/g at 3000 mA/g) and excellent stability (no fading at fast rate during more than 500 cycles). Cation vacancies in hollow iron oxide nanoparticles are also found to be responsible for the enhanced capacity in the conversion reactions. We monitored in situ structural transformation of hollow iron oxide nanoparticles by synchrotron X-ray absorption and diffraction techniques that provided us clear understanding of the lithium intercalation processes during electrochemical cycling.

Evaluating the performance of nanostructured materials as lithium-ion battery electrodes

“…Although early work on Fe2O3 anodes resulted in high initial capacities, much of the capacity was lost with extended cycling. More recently, advanced Fe2O3 structures such as nanoflakes [166], nanocapsules [167], nanodiscs [168], hollow nanoparticles [169], nanotubes [170], and reduced-graphene/Fe2O3 nanocomposites [171] have emerged with enhanced Li-ion performance. Liu et al [170], prepared 1D α-Fe2O3 and C-Fe2O3 nanotubes grown directly on conducting substrates by a so-called "sacrificial template-accelerated hydrolysis" (STAH) method, using arrays of ZnO nanowires as hard templates.…”

“…Such examples outline the impact of structural modification on the electrochemical performance of Li-ion anodes. Hollow α-Fe2O3 nanocapsules [167], reduced-graphene/Fe2O3 nanocomposites [171] and γ-Fe2O3 nanoparticles [169] in particular, have also shown high capacities in the anodic region (0.01-3 V). Hematite nanocapsules, prepared by coating spindle-like β-FeCOOH with SiO2 followed by the thermal treatment and wet-chemical etching of the SiO2 shell, displayed capacities as high as 888 mA h g -1 after 30 cycles [167].…”

“…Hematite nanocapsules, prepared by coating spindle-like β-FeCOOH with SiO2 followed by the thermal treatment and wet-chemical etching of the SiO2 shell, displayed capacities as high as 888 mA h g -1 after 30 cycles [167]. In contrast, hollow γ-Fe2O3 nanoparticles, annealed between two layers of MWCNTs at 200 °C, exhibited initial capacities in excess of 1000 mA h g -1 [169]. The high capacity of the hollow γ-Fe2O3 nanoparticles was attributed to Fe cation vacancies in the host γ-Fe2O3 structure which could act as additional Li + storage sites at higher voltages, while the hollow morphology enabled rapid Li + transport and structural support during the electrochemically-induced phase transitions.…”

High-rate lithiation-induced reactivation of mesoporous hollow spheres for long-lived lithium-ion batteries

“…Hierarchically meso-and nanoporous hollow spheres are recognized as promising electrode materials for electrochemical energy storages [19][20][21][22][23][24] , and the unique structure provides an enhanced surface-to-volume ratio and reduced lengths for both mass and charge transports. The hollow sphere also provides extra space to mitigate volume expansion/extraction, thus displaying enhanced cycling stabilities, particularly at low current densities.…”

Carbon-decorated iron oxide hollow granules formed using a silk fibrous template: lithium-oxygen battery and wastewater treatment applications

“…Particularly, the hollow structures can offer rapid ion transport with improved electronic and chemical kinetics. [19][20][21] Through ripening (or hollowing) and reduction processes, the prepared iron oxide HGs are modified to offer important merits: (i) high specific surface area for available active sites; (ii) hierarchical porosity for short diffusion pathways; (iii) control of Fe 2+ /Fe 3+ redox system for high electrocatalytic activity; and (iv) defective carbon formation for removal of organic pollutants. To demonstrate the above merits, we applied the C/Fe 3 O 4 HGs and Fe 2 O 3 HGs in the Li-O 2 battery cathode and the adsorbent of pollutants.…”