Study of the Lithium Storage Mechanism of N‐Doped Carbon‐Modified Cu₂S Electrodes for Lithium‐Ion Batteries

Abstract

Owing to their high specific capacity and abundant reserve, CuxS compounds are promising electrode materials for lithium‐ion batteries (LIBs). Carbon compositing could stabilize the CuxS structure and repress capacity fading during the electrochemical cycling, but the corresponding Li+ storage mechanism and stabilization effect should be further clarified. In this study, nanoscale Cu2S was synthesized by CuS co‐precipitation and thermal reduction with polyelectrolytes. High‐temperature synchrotron radiation diffraction was used to monitor the thermal reduction process. During the first cycle, the conversion mechanism upon lithium storage in the Cu2S/carbon was elucidated by operando synchrotron radiation diffraction and in situ X‐ray absorption spectroscopy. The N‐doped carbon‐composited Cu2S (Cu2S/C) exhibits an initial discharge capacity of 425 mAh g−1 at 0.1 A g−1, with a higher, long‐term capacity of 523 mAh g−1 at 0.1 A g−1 after 200 cycles; in contrast, the bare CuS electrode exhibits 123 mAh g−1 after 200 cycles. Multiple‐scan cyclic voltammetry proves that extra Li+ storage can mainly be ascribed to the contribution of the capacitive storage.

Sulfur-Bridged Bonds Boost the Conversion Reaction of the Flexible Self-Supporting MnS@MXene@CNF Anode for High-Rate and Long-Life Lithium-Ion Batteries

“…Recently, transition-metal sulfides (TMSs) as conversion reaction-type materials have become one of the anode alternatives due to their unique physicochemical property (such as good electrical conductivity, mechanical stability, and adjustable reactivity) and high theoretical capacity, which is higher than that of graphite. Common transition-metal sulfides used as anodes include ferric sulfides, cobalt sulfides, nickel sulfides, copper sulfide, manganese sulfides, , and so on. Since the M–S bonds are weaker than M–O bonds (M = metal) in traditional metal oxides, metal sulfides generally have a stronger reversibility and a higher Coulombic efficiency. , …”

Interface Optimization of Cu2S Nanoparticles by Loading N-Doped Carbon for Efficient Sodium-Ion Storage

“…: ICSD 41911), while the CuS undergoes reduction to Cu 2 S by the loaded carbon, resulting in the formation of a tetragonal phase (registry no. : ICSD 95398, space group: P4 3 2 1 2, as shown in Figure 2b) [25,26]. Additionally, bare Cu 2 S exhibits the same tetragonal phase as Cu 2 S/PG, as evident from Figure 2c.…”

“…Firstly, Copper Sulfide (CuS) nanoparticles were fabricated utilizing the precipitation technique inspired by the previous report [25], as illustrated in Figure 1a. Copper nitrate trihydrate (Cu(NO 3 ) 2 •3H 2 O) with purity ≥98.0% and thioacetamide (C 2 H 5 NS) with purity ≥99.0% were obtained from Sigma-Aldrich (St. Louis, MO, USA).…”

Design of High‐Capacity MoS3 Decorated Nitrogen Doped Carbon Coated Cu2S Electrode Structures with Dual Heterogenous Interfaces for Outstanding Sodium‐Ion Storage

“…And Cu 2 S possesses a high electrical conductivity (a small band gap of 1.2 eV), and suitable voltage platform, making it one of the prospective anode materials for new SIBs. [9,10] Despite the above mentioned advantages, Cu 2 S inevitably owns some drawbacks such as the relatively low theoretical capacity (337 mAh g −1 ) and large volume fluctuation in the discharge/charge process. [11,12] Currently, in order to solve these scientific issues, two effective strategies such as the design of special nano-structures and the composites with carbon-based materials have been commonly adopted by researchers.…”