N‐Doped Carbon‐Coated Mixed‐Phase SnS–SnS₂ Anode with Carbon Nanofibers Skeleton for Improving Dual‐Ion Battery in Concentrated Electrolyte

Abstract

Metal sulfides exhibit great potential for anode material due to the lamellar structure. However, the intrinsic low conductivity and large volume expansion result in poor cycle stability. Herein, a porous hierarchical structure (SnS–SnS2)–NC–CF anode material composed of carbon nanofibers skeleton and N‐doped carbon is designed, and a full dual‐ion battery based on the anode is constructed, coupled with natural graphite and high‐concentration electrolyte (6 M LiTFSI + 5% vinylene carbonate). The graphite/(SnS‐SnS2)–NC–CF dual‐ion battery shows a high initial discharge specific capacity up to 154.3 mAh g−1 at a current density of 100 mA g−1 in a working voltage window of 1.0–4.0 V. Also, the battery obtains a considerable capacity of 67.1 mAh g−1 at the high current density of 1000 mA g−1 and achieves an excellent cycling performance up to 2000 cycles with remarkable Coulombic efficiency near 100%. In addition, the battery exhibits a low self‐discharge of 1.83% h−1 and superior fast charge performance. Furthermore, the results of the X‐ray diffraction and scanning electron microscope characterizations further demonstrate good reversibility and stability. Consequently, this work provides a feasible strategy for the design of a high performance dual‐ion battery energy storage device.

An Ultrahigh‐Capacity Dual‐Ion Battery Based on a Free‐Standing Graphite Paper Cathode and Flower‐Like Heterojunction Anode of Tin Disulfide and Molybdenum Disulfide

“…Consequently, the self-discharge rate can be calculated as 0.028 % h À 1 according to the reported literature, which is far below the previous work. [23,27,30,52,53] Besides, the residual capacity at 200 mA g À 1 is 190.5 mAh g À 1 (the control battery: 207.4 mAh g À 1 )(Figure 5c and 5d), and the residual capacity at 400 mA g À 1 is 131.6 mAh g À 1 (the control battery: 175.8 mAh g À 1 )(Figure 5e and 5 f). Likewise, the self-discharge rates of 200 mA g À 1 and 400 mA g À 1 are 0.016 % h À 1 and 0.05 % h À 1 , respectively.…”

“…SnS 2 belongs to the post metal sulfides, possesses a large inter-layer distance (0.59 nm) and high theoretical capacity (645 mAh g À 1 ). [23][24][25] Therefore, combining the SnS 2 and MoS 2 to design a binary metal sulfides heterojunction can serve as a promising anode material for energy storage, contributing to improve the capacity and performance of the dual-ion battery.…”

Fundamental Understanding and Optimization Strategies for Dual-Ion Batteries: A Review

“…Although the rapid development of DIBs has been achieved, the related research is still at their early stage. More efforts should be devoted to exploring novel electrode materials and electrolytes tailored for high-performance DIBs [ 37 , 39 – 43 ]. Besides, effective strategies and characterization techniques are needed to deeply understand the fundamental working mechanisms of proposed DIBs.…”