Universal Strategy for Preparing Highly Stable PBA/Ti₃C₂T_x MXene toward Lithium-Ion Batteries via Chemical Transformation

Abstract

Prussian blue analogues (PBAs) are believed to be intriguing anode materials for Li + storage because of their tunable composition, designable topologies, and tailorable porous structures, yet they suffer from severe capacity decay and inferior cycling stability due to the volume variation upon lithiation and high electrical resistance. Herein, we develop a universal strategy for synthesizing small PBA nanoparticles hosted on two-dimensional (2D) MXene or rGO (PBA/MX or PBA/rGO) via an in situ transformation from ultrathin layered double hydroxides (LDH) nanosheets. 2D conductive nanosheets allow for fast electron transport and guarantee the full utilization of PBA even at high rates; at the meantime, PBA nanoparticles effectively prevent 2D materials from restacking and facilitate rapid ion diffusion. The optimized Ni 0.8 Mn 0.2 -PBA/MX as an anode for lithium-ion batteries (LIBs) delivers a capacity of 442 mAh g −1 at 0.1 A g −1 and an excellent cycling robustness in comparison with bare PBA bulk crystals. We believe that this study offers an alternative choice for rationally designing PBA-based electrode materials for energy storage.

Nb2CTx MXene Cathode for High-Capacity Rechargeable Aluminum Batteries with Prolonged Cycle Lifetime

“…Owing to their impressive electrochemical properties, versatile surface chemistry, tunable optical absorption, and solution processability, MXenes (e.g., Ti 3 C 2 T x , V 2 CT x , and Nb 2 CT x ) have been utilized in a plethora of applications, including energy storage, supercapacitors, energy harvesting, optoelectronics, electromagnetic interference shielding, sensing, and solar-driven applications . Several reports have emphasized the advantages of MXene for charge storage. − In 2017, a V 2 CT x MXene cathode-based aluminum-ion battery was reported, showing a specific capacity of 90 mAh g –1 after 100 cycles at a current density of 100 mA g –1 . This report pioneered the utilization of layered MXene as cathode materials for aluminum-ion batteries; however, the specific capacity and cyclic life are yet to be optimized.…”

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

“…Therefore, as shown in digital photos, Mn 3 O 4 nanosheets could be well-dispersed in deionized (DI) water to form a colloidal solution, as validated by the Tyndall effect, and the mixed solution remains stable without observing flocculation after mixing with the MXene colloidal solution due S4, the as-prepared 2D Mn 3 O 4 presents a two-layer nanostructure, and MXene with one to two-layer nanostruc-ture. Like any other 2D material, the pristine MXene film (10 mg) suffers from the layer-restacking issue due to strong and uniform surface interionic forces between the layers, 37,38 leading to a dense structure with a thickness of 5 μm (Figure S5) and a low specific surface area of 0.79 m 2 g −1 (Table S1). During vacuum filtering of the combination of Mn 3 O 4 and MXenes, the difference in interionic forces between Mn 3 O 4 and MXenes permits their random stacking, resulting in more spacing and substantially loose structure for the Mn 3 O 4 -MXene-8-2 film.…”

Sandwich-like Na2Ti3O7 Nanosheet/Ti3C2 MXene Composite for High-Performance Lithium/Sodium-Ion Batteries

“…The fitted b values of the NTO@MXene composite were 0.82 and 0.84, showing that the electrochemical process of the composite was dominantly capacity-controlled (Figure b). The proportionate percentage of capacitance storage contributions at a specified voltage was computed by the subsequent equation: i ( V ) = k 1 ν + k 2 v 1 / 2 …”