MXene-Based Electrode with Enhanced Pseudocapacitance and Volumetric Capacity for Power-Type and Ultra-Long Life Lithium Storage

Abstract

Powerful yet thinner lithium-ion batteries (LIBs) are eagerly desired to meet the practical demands of electric vehicles and portable electronic devices. However, the use of soft carbon materials in current electrode design to improve the electrode conductivity and stability does not afford high volumetric capacity due to their low density and capacity for lithium storage. Herein, we report a strategy leveraging the MXene with superior conductivity and density to soft carbon as matrix and additive material for comprehensively enhancing the power capability, lifespan, and volumetric capacity of conversion-type anode. A kinetics favorable 2D nanohybrid with high conductivity, compact density, accumulated pseudocapacitance, and diffusion-controlled behavior is fabricated by coupling TiC MXene with high-density molybdenum carbide for fast lithium storage over 300 cycles with high capacities. By replacing the carbonaceous conductive agent with TiC MXene, the electrodes with better conductivity and dramatically reduced thickens could be further manufactured to achieve 37-40% improvement in capacity retention and ultra-long life of 5500 cycles with extremely slow capacity loss of 0.002% per cycle at high current rates. Ultrahigh volumetric capacity of 2460 mAh cm could be attained by such MXene-based electrodes, highlighting the great promise of MXene in the development of high-performance LIBs.

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

“…As shown in Figure a, the “pillar effect” of Sn 4+ between Ti 3 C 2 layers and the synergistic effect between the Ti 3 C 2 matrix and Sn 4+ lead to a superior reversible volumetric capacity of 1375 mAh cm −3 (at 216.5 mA cm −3 ) and excellent rate performances . Recently, 2D high‐density η‐MoC/MXene/C nanocomposite electrodes (Figure b) have displayed an ultrahigh volumetric capacity (2460 mAh cm −3 ), which is over four times higher than that of graphite anode (550 mAh cm −3 ), as well as extremely slow capacity loss (0.002% per cycle at high current rate) . Zhao et al .…”

“…The demands for thinner LIBs keep surging in order to satisfy the ever‐increasing flexible electronics markets. As a result, the pursuit of high volumetric LIBs is of practical significance . MXenes hold a great promise for high volumetric energy storage due to their remarkable electrical conductivity, low Li + diffusion barrier and superior tap density.…”

“…b) i) A comparison between reported anodes and η‐MoC/MXene/C with CB or MXene as the conductive agent in volumetric capacity; and ii) long‐term cycling stability of η‐MoC/MXene/C+ MXene electrodes at high current rate of 10 A g –1 . All the electrochemical tests are conducted between 0.01 and 3.0 V. Reproduced with permission from ref . Copyright 2018 American Chemical Society.…”

A Ternary Fe1−xS@Porous Carbon Nanowires/Reduced Graphene Oxide Hybrid Film Electrode with Superior Volumetric and Gravimetric Capacities for Flexible Sodium Ion Batteries

“…[23,38,39] Thus, it is necessary to evaluate the gravimetric and volumetric capacities of these paper electrodes with even higher areal mass loading and density. [23,38,39] Thus, it is necessary to evaluate the gravimetric and volumetric capacities of these paper electrodes with even higher areal mass loading and density.…”

MXene‐Based Composites: Synthesis and Applications in Rechargeable Batteries and Supercapacitors

“…[89] Due to the above characteristics, it may be possible to graft materials containing a special element and subsequently achieve doping by thermal decomposition. A more favorable material is some form of carbon, [127,249,250] which contributes to both advantageously. [122] Moreover, some nonmetallic elements such as sulfur have a high theoretical capacity, so the capacity of the doped material is likely to increase.…”