Stabilized Molybdenum Trioxide Nanowires as Novel Ultrahigh‐Capacity Cathode for Rechargeable Zinc Ion Battery

Abstract

Exploration of high‐performance cathode materials for rechargeable aqueous Zn ion batteries (ZIBs) is highly desirable. The potential of molybdenum trioxide (MoO 3 ) in other electrochemical energy storage devices has been revealed but held understudied in ZIBs. Herein, a demonstration of orthorhombic MoO 3 as an ultrahigh‐capacity cathode material in ZIBs is presented. The energy storage mechanism of the MoO 3 nanowires based on Zn 2+ intercalation/deintercalation and its electrochemical instability mechanism are particularly investigated and elucidated. The severe capacity decay of the MoO 3 nanowires during charging/discharging cycles arises from the dissolution and the structural collapse of MoO 3 in aqueous electrolyte. To this end, an effective strategy to stabilize MoO 3 nanowires by using a quasi‐solid‐state poly(vinyl alcohol)(PVA)/ZnCl 2 gel electrolyte to replace the aqueous electrolyte is developed. The capacity retention of the assembled ZIBs after 400 charge/discharge cycles at 6.0 A g −1 is significantly boosted, from 27.1% (in aqueous electrolyte) to 70.4% (in gel electrolyte). More remarkably, the stabilized quasi‐solid‐state ZIBs achieve an attracting areal capacity of 2.65 mAh cm −2 and a gravimetric capacity of 241.3 mAh g −1 at 0.4 A g −1 , outperforming most of recently reported ZIBs.

Coupling PEDOT on Mesoporous Vanadium Nitride Arrays for Advanced Flexible All‐Solid‐State Supercapacitors

“…[15][16][17] Instead, pseudocapacitive materials (e.g., metal oxides, metal nitrides, metal sulfides) are becoming one of the favorites because of their high capacitance and energy density. [18][19][20][21] However, metal oxides and metal sulfides show poor intrinsic electronic conductivity, and thereby lead to compromised power/energy performance. [22,23] Meanwhile, metal nitride, typically vanadium nitride (VN), has been demonstrated to realize both high energy/power density in view of its high electrical conductivity (1.67 × 10 6 S m −1 ), wide potential window (1.0-1.2 V), and superior electrochemical redox reactivity.…”

Controllable synthesis and surface modification of molybdenum oxide nanowires: a short review

“…The resulting composite materials exhibited outstanding electrochemical performances with a reversible capacity owing to the formation of suitable ion transfer pathways. Similarly, the MoO 3 nanowire decay can also be stabilized via applying electrolytes such as quasi-solid-state poly(vinyl alcohol) (PVA)/ZnCl 2 gel during the charging/discharging cycles, and thereby employing as the Zn 2+ storage electrode with ultrahigh-capacity cathode for rechargeable Zn ion batteries [42]. Nanowire composites are also further modified with additional materials such as high thermal conductive materials (graphene sheet) for improved supercapacitors.…”

Two‐Dimensional Transition Metal Carbides and Nitrides (MXenes): Synthesis, Properties, and Electrochemical Energy Storage Applications

“…Nowadays, energy storage devices (ESDs) are playing a crucial role in smart electronics and wearable textiles. Rechargeable batteries (including Li, Na, K, Zn‐ions) as well as supercapacitors are being considered as promising energy storage devices for sustainable development of smart electronics . While batteries are known for their high energy density, the cycle life and charging/discharging rate are unfavorable in most cases .…”