Flexible Mn₃O₄/MXene Films with 2D–2D Architectures as Stable and Ultrafast Anodes for Li-Ion Batteries

Abstract

Mn3O4 is regarded as a promising anode material for lithium-ion batteries (LIBs) based on its ultrahigh theoretical capacity (937 mAh g–1) and low cost but suffers from poor electronic conductivity and large volume variation during the lithiation/delithiation process, which result in dramatic capacity fading and inferior rate capability. Ti3C2T x MXene, a novel two-dimensional transition metal carbide with metallic conductivity, excellent mechanical properties, and hydrophilic surface, could be an ideal candidate to improve the lithium storage performance of Mn3O4. Here, a unique flexible, 2D–2D Mn3O4/MXene film is fabricated by assembling 2D Mn3O4 with Ti3C2T x nanosheets through a simple vacuum filtration approach. In this unique 2D–2D nanostructure, MXene nanosheets buffer the volume change of Mn3O4 during the charge/discharge process. Moreover, the introduction of MXene enables the fabricated 2D–2D nanostructure with excellent flexibility and can be directly used as an electrode for LIBs, which is beneficial for enhancing the energy density of the assembled batteries. As a result, the flexible film of Mn3O4-MXene-8-2 shows excellent lithium storage performances in terms of specific capacity (931 mAh g–1 at 0.05 A g–1), rate capability (624 mAh g–1 at 1 A g–1), and cycling stability, demonstrating its great potential for the application in LIBs.

V2CTx MXene-Encapsulated Liquid Metal Composite as an Anode for Wide-Temperature Li-Ion Batteries

“…This means that LM is beneficial to the compact SEI due to the uniform and dense Li deposition, which prevents further reactions between the electrolyte and electrode, thereby providing stable cycling performance at low operating temperatures. Notably, compared with other MXene-based and low-temperature anode materials, our composites display the highest specific capacity and better low-temperature electrochemical performance (Figure g). − …”

Ultra‐Efficient Synthesis of Nb4C3Tx MXene via H2O‐Assisted Supercritical Etching for Li‐Ion Battery

“…b = 0.5 implies an ideal diffusion behavior (diffusion-controlled process), and b = 1 represents a capacitive charge storage mechanism. [48,49] As shown in Figure 5g, the b values of the cathodic and anodic peaks of the Nb 4 C 3 T x MXene electrode are 0.83 and 0.82, respectively, suggesting that the charge storage mechanism of the Nb 4 C 3 T x electrode is dominated by the capacitive process. The proportion of capacitive and diffusion-controlled process can be calculated using the following equation:…”

Rational design of CoP@Ni(OH)2 bilayer nanosheets for high-performance supercapacitors

“…The fitting results of the anodic and cathodic peaks exhibited good linear relationships because of the large correlation coefficients, validating that the diffusion-controlled process governed the charge storage. 32 Fig. 5b and Fig.…”