Fabrication Of Cathode Materials Research Articles

Dual Protection Strategy by Constructing MXene-Coated Cu2Se-Cu1.8Se Heterojunction and CMK-3 Modification for High-Performance Aluminum-Ion Batteries.

The fabrication of cathode materials with ideal kinetic behavior is important to improve the electrochemical performance of aluminum-ion batteries (AIBs). Transition metal selenides have the advantages of abundant reserves and high discharge specific capacity and discharge voltage plateau, which makes them a promising material for rechargeable AIBs. It is well-known that the low structural stability and relatively poor reaction kinetics pose a considerable challenge to the development of AIBs. The cubic structure of Cu2Se-Cu1.8Se can adapt to the volume change of the active material during cycling and facilitate the intercalation and deintercalation of chloroaluminate anions in the cathode material. We created a two-fold protection mechanism for AIBs with a CMK-3 modified separator and a Cu2Se-Cu1.8Se heterojunction coated with MXene in order to better mitigate the detrimental impacts. In addition to offering numerous electronic transmission routes, MXene and CMK-3 help prevent the solubilization of active species. This novel design enables the Cu2Se-Cu1.8Se@MXene composite to have a high initial discharge capacity of 705.5 mAh g-1 at 1.0 A g-1. Even after 1500 cycles at 2.0 A g-1, the capacity is still maintained at 225.1 mAh g-1. Furthermore, the reaction mechanism of AlCl4- intercalated/deintercalated into Cu2Se-Cu1.8Se heterojunction is revealed during charge/discharge. This work to construct novel cathode materials has greatly improved the electrochemical performance of AIBs.

Ultrathin hybrid nanobelts of single-crystalline VO2 and Poly(3,4-ethylenedioxythiophene) as cathode materials for aqueous zinc ion batteries with large capacity and high-rate capability

Design and fabrication of cathode materials with large capacity and high-rate capability in aqueous zinc ion batteries (AZIBs) are challenging. Herein, ultrathin hybrid nanobelts comprising single-crystalline VO2 and poly(3,4-ethylenedioxythiophene) (PEDOT) (designated as VO2-PEDOT) are synthesized as cathode materials for the AZIBs. The nanobelts have a thickness below 10 nm, large amount of exposed VO2 (001) facets and discrete PEDOT conductive layers. Systematic structural and electrochemical assessment reveals that simultaneous proton and Zn2+ insertion into the VO2 host is efficient in the Zn(CF3SO3)2 electrolyte due to synergistic effects rendered by unique structure of the VO2-PEDOT nanobelts. The Zn/VO2-PEDOT battery that shows a storage mechanism involving two carriers delivers extraordinary performance including a high capacity of 540 mAhg−1 with 36.3% beyond a high operating voltage of 0.7 V at −0.05 Ag−1, high rate capability of 231.2 mAhg−1 at 10 Ag−1, excellent cycling stability up to 1000 cycles with capacity retention of 84.5%. Moreover, the 50 μm thick freestanding electrode consisting of ultrathin VO2-PEDOT nanobelts has a large areal capacity of 1.35 μAhcm−2 at 5 Ag−1. The results provide mechanistic insights into the electrochemistry of VO2-based cathodes and reveal a new strategy to improve the performance of the AZIBs especially with regard to grid-scale energy storage.

Advanced Cathode Materials for Sodium‐Ion Batteries: What Determines Our Choices?

Among the various energy solutions, lithium‐ion batteries (LIBs) play an important role in the process of the transition from fossil fuels to renewables. However, the necessity to replace lithium with cheaper alternatives due to its scarcity has recently attracted great interest to developing sodium‐ion batteries (SIBs). Hence, the discovery and development of suitable cathode materials that exhibit high specific capacity, good cycling stability, and high energy density are actively pursued. Today's SIB technology continues to be driven by the performance of the cathode materials. Here, recent advancements made regarding the cathode of SIBs are summarized, covering some of the fundamental aspects of SIBs, synthetic protocols, and characteristics of existing and prospective cathode materials used for SIBs. Furthermore, some of the latest achievements in the fabrication of cathode materials, as a practical demonstration on their viability, are also discussed. With better understanding of these topics, the rationales behind their enhanced electrochemical performances are revealed and explained. Last but not least, imminent challenges and future prospects are also included to provide some insights into the possible development of advanced cathode materials for SIBs.

Synthesis of high-voltage spinel LiNi0.5Mn1.5O4 material for lithium-ion batteries by a metal-cholate supramolecular hydrogel as precursor

High-voltage cathode material LiNi0.5Mn1.5O4 has been first synthesized by a novel metal-cholated supramolecular hydrogel as precursor. The structural analysis was investigated by X-ray powder diffraction, scanning electronic microscope, and Fourier transform infrared spectroscopy. The results indicated that the as-products possessed well constructed spinel structure and high crystallinity and pure phase through adding optimal amount of cholic acid. The electrochemical properties were also investigated, and its results showed that the LiNi0.5Mn1.5O4 material exhibited enhanced rate capacity and cycling properties as electrode materials in lithium cells mainly due to the improved crystallinity and higher pure phase. In a word, this new approach provides an alternative and promising route for the fabrication of cathode materials with perfect octahedron structure and excellent electrochemical properties using metal-driven hydrogels as template.