Fe₂O₃/MoO₃@NG Heterostructure Enables High Pseudocapacitance and Fast Electrochemical Reaction Kinetics for Lithium-Ion Batteries

Abstract

Transition metal oxides (TMOs) hold great potential for lithium-ion batteries (LIBs) on account of the high theoretical capacity. Unfortunately, the unfavorable volume expansion and low intrinsic electronic conductivity of TMOs lead to irreversible structural degradation, disordered particle agglomeration, and sluggish electrochemical reaction kinetics, which result in perishing rate capability and long-term stability. This work reports an Fe 2 O 3 /MoO 3 @NG heterostructure composite for LIBs through the uniform growth of Fe 2 O 3 /MoO 3 heterostructure quantum dots (HQDs) on the N-doped rGO (NG). Due to the synergistic effects of the "couple tree"-type heterostructures constructed by Fe 2 O 3 and MoO 3 with NG, Fe 2 O 3 /MoO 3 @NG delivers a prominent rate performance (322 mA h g −1 at 20 A g −1 , 5.0 times higher than that of Fe 2 O 3 @NG) and long-term cycle stability (433.5 mA h g −1 after 1700 cycles at 10 A g −1 ). Theoretical calculations elucidate that the strong covalent Fe−O−Mo, Mo−N, and Fe−N bonds weaken the diffusion energy barrier and promote the Li + -ion reaction to Fe 2 O 3 /MoO 3 @NG, thereby facilitating the structural stability, pseudocapacitance contribution, and electrochemical reaction kinetics. This work may provide a feasible strategy to promote the practical application of TMO-based LIBs.

Heteroatoms‐Doped Mesoporous Carbon Nanosheets with Dual Diffusion Pathways for Highly Efficient Potassium Ion Storage

“…In Figure S23b (Supporting Information), the diffusion‐ and capacitive‐controlled contributions are separated at the corresponding voltage to quantitatively determine the normalized contribution ratios. [ 50 ] It should be noted that as the scan rate increases from 0.2 to 2 mV s −1 , the capacitive‐controlled contributions of the NOS‐C‐900 anode increase from 23% to 67% (Figure 4b; Figure S24, Supporting Information), demonstrating the capacitive‐controlled effect gradually dominates, which is advantageous to achieve high rate performance. The diffusion coefficients of K + (D K + ) were explored by constant current intermittent titration technique (GITT) (Figure 4c,d; Figures S25 and S26, Supporting Information).…”

Low volume expansion hierarchical porous sulfur-doped Fe2O3@C with high-rate capability for superior lithium storage

“…[13][14][15] Among TMOs, Fe 2 O 3 shows ultrahigh theoretical capacity (1007 mA h g −1 ), excellent reversible property, and low price, making it an attractive material. [16][17][18] However, the same drawbacks as TMOs result in poor performance of Fe 2 O 3 in lithium storage. 19,20 To obtain Fe 2 O 3 with excellent electrochemical performance, diverse strategies have been adopted.…”

Flowers Like α-MoO3/CNTs/PANI Nanocomposites as Anode Materials for High-Performance Lithium Storage

“…In this context, lithium-ion batteries (LIBs) have been proved as promising energy storage devices that are widely used in daily life, such as in hybrid electric vehicles, space exploration, aviation [7] and portable electronic devices [8][9][10], owing to high power densities, environmental friendliness, long cycle lives, low self-discharges, high energy densities, small ionic sizes (which permit fast Li + intercalation in solids) that are a main factor for fast charging, cyclic stabilities, small memory effects and high open circuit voltages [11,12]. To fulfill the current energy demands, the electrochemical performance of LIBs including cycle life, capacity, power density and charging speed should be enhanced [7].…”