Realizing Ultrafast and Robust Sodium-Ion Storage of Iron Sulfide Enabled by Heteroatomic Doping and Regulable Interface Engineering

Abstract

Fe-based sulfides are a promising type of anode material for sodium-ion batteries (SIBs) due to their high theoretical capacities and affordability. However, these materials often suffer from issues such as capacity deterioration and poor conductivity during practical application. To address these challenges, an N-doped Fe7S8 anode with an N, S co-doped porous carbon framework (PPF-800) was synthesized using a template-assisted method. When serving as an anode for SIBs, it delivers a robust and ultrafast sodium storage performance, with a discharge capacity of 489 mAh g−1 after 500 cycles at 5 A g−1 and 371 mAh g−1 after 1000 cycles at 30 A g−1 in the ether-based electrolyte. This impressive performance is attributed to the combined influence of heteroatomic doping and adjustable interface engineering. The N, S co-doped carbon framework embedded with Fe7S8 nanoparticles effectively addresses the issues of volumetric expansion, reduces the impact of sodium polysulfides, improves intrinsic conductivity, and stimulates the dominant pseudocapacitive contribution (90.3% at 2 mV s−1). Moreover, the formation of a stable solid electrolyte interface (SEI) film by the effect of uniform pore structure in ether-based electrolyte produces a lower transfer resistance during the charge–discharge process, thereby boosting the rate performance of the electrode material. This work expands a facile strategy to optimize the electrochemical performance of other metal sulfides.

Introduction of SnS2 to Regulate the Ferrous Disulfide Phase Evolution for the Construction of Triphasic Heterostructures Enabling Kinetically Accelerated and Durable Sodium Storage

“…[ 26 ] The formation of low‐valence tin would be attributed to the reduction effect of the carbon layer during the sulfidation process. [ 27 ] S 2p peaks have closely spaced spin‐orbit components composed by S 2p 3/2 and S 2p 1/2 with a gap of about 1.16 eV. The S 2p spectrum of FFS‐TH depicted in Figure 2d is composed of metal‐sulfur bonds (Fe─S and Sn─S bonds were distinguished), C─S bonds and absorbed sulfur oxide groups, suggesting a strong chemical bonding to improve the conductivity of carbon matrix.…”

Constructing Abundant Oxygen-Containing Functional Groups in Hard Carbon Derived from Anthracite for High-Performance Sodium-Ion Batteries

“…80.11%, 85.49%, 90.06%, and 94.32% at scan rates from 0.2 mV s −1 to 1.0 mV s −1 , which are all higher than that of B-HC1100 (65.24%, 74.32%, 77.28%, 83.50%, and 88.23%) shown in Figure S10d, indicating the excellent rate capability of A-HC1100. The expanding D Na+ and mesopore structures of A-HC1100 could be the cause of the slightly greater ratio of the capacitive contribution [66][67][68].…”

MoS2/SnS/CoS Heterostructures on Graphene: Lattice-Confinement Synthesis and Boosted Sodium Storage

“…The larger radius of Na + (1.02 Å) than that of Li + (0.76 Å), however, results in the sluggish kinetics of insertion/extraction of Na + into active materials [ 5 , 6 , 7 ] and thus hinders the development and application of SIBs. The limitation has triggered a great deal of effort to develop numerous advanced anode nanomaterials for SIBs, such as carbon-based nanomaterials [ 8 , 9 , 10 , 11 ], metallic alloys [ 12 , 13 , 14 ], two-dimensional (2D) metal carbides (MXenes) [ 15 , 16 , 17 , 18 ], metal dichalcogenides [ 19 , 20 , 21 , 22 ], and metal sulfides. In particular, metal sulfides are considered to be favorable for sodium storage reactions due to their weak metal–sulfur (M–S) bonds, good reversibility and high capacity [ 23 ].…”