Hetero-Element-Doped Molybdenum Oxide Materials for Energy Storage Systems

Abstract

In order to meet the growing demand for the electronics market, many new materials have been studied to replace traditional electrode materials for energy storage systems. Molybdenum oxide materials are electrode materials with higher theoretical capacity than graphene, which was originally used as anode electrodes for lithium-ion batteries. In subsequent studies, they have a wider application in the field of energy storage, such as being used as cathodes or anodes for other ion batteries (sodium-ion batteries, potassium-ion batteries, etc.), and electrode materials for supercapacitors. However, molybdenum oxide materials have serious volume expansion concerns and irreversible capacity dropping during the cycles. To solve these problems, doping with different elements has become a suitable option, being an effective method that can change the crystal structure of the materials and improve the performances. Therefore, there are many research studies on metal element doping or non-metal doping molybdenum oxides. This paper summarizes the recent research on the application of hetero-element-doped molybdenum oxides in the field of energy storage, and it also provides some brief analysis and insights.

Stabilizing Ni-rich high energy cathodes for advanced lithium-ion batteries: the case of LiNi0.9Co0.1O2

“…These experimental observations of lower R ct for doped cathodes correlate well with our suggestion that Mo 6+ doping introduces more electrons into the system and induces, thus, the formation of additional conduction bands near the Fermi level (Figure 4b, d). Moreover, we propose that a new phase Li 2 MoO 4 (lithium molybdate) formed upon synthesizing the Mo and Mo-B-doped samples (Schemes 1 and 3) contributes to modifying the electrode/solution interface of NC90 cathodes due to its tunnel structure and electrochemical activity in Li-cells [65][66][67] . Therefore, lower charge transfer resistance and higher exchange current facilitate ion and electron transport at the interface of doped electrodes, similar to that in NCM85 Mo-doped materials 45 .…”

“…Moreover, we propose that a new phase Li 2 MoO 4 (lithium molybdate) formed upon synthesizing the Mo and Mo-B-doped samples (schemes ( 1) and ( 3)) contributes to modifying the electrode/solution interface of NC90 cathodes due to its tunnel structure and electrochemical activity in Licells. [65][66][67] Therefore, lower charge transfer resistance and higher exchange current facilitate ion and electron transport at the interface of doped electrodes, similar to that in NCM85 Modoped materials. 45 Decreasing the charge-transfer resistances measured from NC90 cycled electrodes dually doped with Mo and B can be explained by a synergistic effect where both dopants modify the electrode/solution interface, as follows: Mo 6+ contributes by the formation of a new conduction band near the Fermi level and a new Li-conducting phase of Li 2 MoO 4 .…”

The versatile family of molybdenum oxides: synthesis, properties, and recent applications

“…MoO 3 and MoO 2 are considered to be exceptional electrode/anode materials because of their low cost, environmentally friendly nature, and high theoretical specific capacity (1117 and 838 mA * h/g for MoO 3 and MoO 2 , respectively) [209][210][211]. Recently, many excellent reviews on this topic have been published [212][213][214][215], and in this section, we will highlight the recent progress in the use of molybdenum oxides to improve their performance in electrochemical energy storage systems.…”

“…In this case, the electronic conductivity is enhanced considerably, particularly in supercapacitors and microbatteries. Another alternative was reviewed by Hu et al [214] in the same year: hetero-elemental-doped molybdenum oxides. The combination of various metals with MoO x results in materials with new architecture and chemical characteristics that can be explored.…”

Humidity-driven degradation of sputtered molybdenum oxide and molybdenum–titanium-oxide thin films

“…Molybdenum oxides are of interest for a broad range of applications due to the variety and tunability of their electronic and optical properties. In recent years, molybdenum oxide (MoO x with 2 r x r 3) has been explored as a catalyst, [1][2][3] for energy storage, 4 in electronics 5 and photodetectors, 6,7 and as a hole-selective material for solar cells [8][9][10] and (organic) light emitting diodes (OLEDs). 11,12 Although the wide range of structures and stoichiometries adopted by MoO x yields such diverse applicability, there is often a common struggle concerning the stability of the material for the targeted application.…”