Electrochemical preparation of porous MoO₃film with a high rate performance as anode for lithium ion batteries

Abstract

A porous MoO 3 film is prepared by electrodeposition on Ni foam substrates and exhibits a capacity of 650 mAh g À1 at a current density of 3 A g À1 as anodes for lithium ion batteries. Electrochemical measurements demonstrate that the outstanding rate performances are due to the improved Li + diffusion kinetics.The possibility of applying rechargeable Li ion batteries (LIBs) in mobile and stationary power storage has generated numerous studies to improve their energy density, power density and cycling life. One area of active research is replacing graphite as the energy storage component in the anode with materials of higher storage capacity. Metal oxides have long been known as Li ion insertion compounds with a much higher capacity than graphite. 1 Unfortunately, bulk metal oxides generally suffer from capacity fading with cycling, especially at higher rates due to the poor kinetics. Thus, various doped metal oxide systems, nanocrystals, and nanocomposites have recently been explored to improve these properties.MoO 3 is a well-known Li + insertion compound and has been investigated during the early years of lithium battery research. 2-4 As an anode material, MoO 3 not only has a superior theoretical specific capacity of nearly 1111 mA h g À1 , 5 which is nearly three times that of graphite, 6 but also has a very stable layered structure. 7,8 This layered structure is able to act as a temporary host for intercalated Li + . 9 However, the poor kinetics of Li + diffusion in bulk layered MoO 3 limits its electrochemical performance. 10 Various forms of MoO 3 materials have been explored to improve the poor kinetics, including doped materials, 11,12 carbon coated nanobelts, 5 and nanomaterials. [13][14][15] In these modification methods, reducing the MoO 3 grain size to nanoscale is more effective for improving the performances of the MoO 3 -based anode. However, good rate performances have been demonstrated rarely in previous reports, and they are still unsatisfactory comparing with other transition metal oxides. 13,16,17 To improve the rate performances of metal oxides, constructing a porous nanostructured film is a significant strategy, 18,19 for example, synthesizing Co 3 O 4 film by a hydrothermal method, 20 preparing Co 3 O 4 film by an ammonia-evaporation-induced method, 21 depositing a hierarchical Fe 2 O 3 /Ni film using chemical vapor deposition, 22 and constructing an Fe 3 O 4 nanorod array film by electrodeposition. 23 These free-standing porous nanostructured films can facilitate Li + transmission in both the electrolyte and anode materials by their porous structure and ultra-small grain size, which improves the rate performance by enhancing the kinetics of Li + diffusion. Among the strategies for constructing free-standing porous nanostructured films, electrodeposition is a simple, controllable and low-cost method that can uniformly deposit thin films onto various metal substrates. However, reports on the preparation of a porous MoO 3 film by electrodeposition directly on the current collector are rare....

Exfoliated MoO3 nanosheets for high-capacity lithium storage

“…This kind of structure is similar to those of layered materials including MoS 2 , WS 2 , BN, which have been successfully exfoliated to ultrathin nanosheets via the liquid-phase exfoliation approach [23], Moreover, bulk MoO 3 is commercially available, widely abundant, and electrochemically active. Therefore, the layer structured bulk α-MoO 3 material can be an excellent precursor for the fabrication of MoO 3 nanosheets for lithium storage [24,25].…”

Phase-pure β-NiMoO4 yolk-shell spheres for high-performance anode materials in lithium-ion batteries

“…The oxidation of metallic Ni to NiO x also contributed to the anodic peak located at approximately 1.8 V [40][41][42]. In the subsequent cycles, the peaks for the different reduction/oxidation peak pairs of 0.7/1.4 and 1.4/ 1.8 V are reversible because of lithium insertion/extraction with MoO 3 [39,42]. In addition, the cathodic/anodic peaks at 1.4/1.8 V are related to the oxidation of metallic Ni to NiO x .…”

“…6a) in the voltage range of 0.001-3 V vs. Li/Li+ with a scan rate 0.07 mV s À1 using coin-type half-cells with a Li counter electrode. During the first cycle, there were broad cathodic humps at 0.3-0.4 V and 0.6 V, indicating the reduction of NiMoO 4 to each metallic nanograin and amorphous Li 2 O phases [39][40][41]. The peak at 1.7 V, only observed in the first cathodic sweep, most likely results from the formation of a solid electrolyte interface (SEI) layer [39].…”

“…During the first cycle, there were broad cathodic humps at 0.3-0.4 V and 0.6 V, indicating the reduction of NiMoO 4 to each metallic nanograin and amorphous Li 2 O phases [39][40][41]. The peak at 1.7 V, only observed in the first cathodic sweep, most likely results from the formation of a solid electrolyte interface (SEI) layer [39]. The anodic peaks at 1.4 and 1.8 V in the first anodic sweep are attributed to the oxidation of metallic Mo to Mo 4+ and metallic Mo 4+ to Mo 6+ [37,42].…”

Lithium storage study on MoO3-grafted TiO2 nanotube arrays

“…Considering low electronic conductivity and high volume expansion, Yu et al (2014) synthesized porous MoO 3 thin films and elucidated better performance as compared to bulk MoO 3 . Zhao et al (2013) Herein, TNAs were grown at Ti substrate and consecutive annealing transforms TNAs in anatase phase. The porous MoO 3 were grafted using a facile hydrothermal method which facilitate high yield product ( Fig.…”