Layered Tin Phosphide Composites as Promising Anodes for Lithium-Ion Batteries

Abstract

Tin phosphides have garnered considerable attention as promising anode materials for lithium-ion batteries (LIBs) due to their high theoretical capacities and earth abundance of constituent elements. Particularly, the rhombohedral Sn3P4 compound, a long-proven phase of tin phosphides, remains unexplored for LIBs. In this study, a solid-state reaction was employed to prepare Sn3P4-based composites as anodes for LIBs. The layered Sn3P4/Sn4P3 composite with the highest Sn3P4 percentage of 80.5% shows an impressive electrochemical performance when carboxymethylcellulose sodium and super P were adopted as the binder and conductive agent, respectively. The higher theoretical capacity of the dominated Sn3P4 in the composites compared to Sn4P3 and the enhanced charge transfer with carbon coating contribute to the improved rate capability and cycle life of Sn3P4/Sn4P3@C composites. Specifically, the resultant Sn3P4/Sn4P3@C anode shows a highly reversible capacity (1140 mAh g–1 at 0.1 A g–1 after the initial five cycles), a considerable rate capability (750 mAh g–1 at 2.0 A g–1), and a good durability (513 mAh g–1 after 100 cycles at 1.0 A g–1). The intrinsic composition of Sn and P coupled with the layered structure accounts for such a superior Li-storage performance. Our findings indicate that layered Sn3P4-based materials are promising candidate anodes for next-generation LIBs.

Synthesis of Free‐Standing Tin Phosphide/Phosphate Carbon Composite Nanofibers as Anodes for Lithium‐Ion Batteries with Improved Low‐Temperature Performance

“…The dark‐colored amorphous phase could be attributed to Sn x PO 4, while different interplanar spacings of 0.225 and 0.29 nm imply the (110) plane of Sn x P and (200) plane of P‐doped Sn, respectively. [ 10,26 ]…”

“…The dark-colored amorphous phase could be attributed to Sn x PO 4, while different interplanar spacings of 0.225 and 0.29 nm imply the (110) plane of Sn x P and (200) plane of P-doped Sn, respectively. [10,26] Figure 4 illustrates the possible effect mechanism of the Sn:P molar ratio on the composition and particle size of samples. The formation of the finer nanoparticles with an increase of the H 3 PO 4 content could be attributed to the formation of a strong phosphate carcass that interacted with functional groups of PVP and formed isolated nucleation sites for the restricted growth of particles.…”

“…[7] Different approaches have been reported to address the abovementioned drawbacks including downsizing of the particle size and carbon coating, mainly aiming at shortening the lithiumionic path and buffering the volume expansion. [7][8][9][10][11] Combining binary compounds with polyanionic phosphates is another promising approach, as they can stabilize the structure and provide migration channels for "guest" ions, further improving the electrochemical performance. [12] Furthermore, tin phosphate (Sn x PO 4 ) itself showed improved LT performance compared to commercial graphite.…”

Insights into Enhancing Electrochemical Performance of Li-Ion Battery Anodes via Polymer Coating

“…Conversion anodes mainly include, but are not limited to, transition metal oxides, sulfides [136], phosphides [137][138][139][140], and nitrides [141][142][143][144]. Herein, polymer coating on the transition metal oxides will be discussed.…”

Two-dimensional layered chromium selenophosphate: advanced high-performance anode material for lithium-ion batteries

“…This promising rate capability could be attributed to the presence of conductive carbon and Ni-B nanoflakes [40,63]. Moreover, the coating of carbon materials can enhance the stability of the electrodes and prevent the layered structure from collapsing during the cycling process [68]. However, the material shows capacity fade as the current is reduced to 100 mA g −1 at the 31 st cycle, with a final value of around 387 mAh g −1 at the 35 th cycle, which is most likely due to partially irreversible electrode material rearrangement during conversion/alloying reactions.…”