Tailoring Nitrogen Terminals on MXene Enables Fast Charging and Stable Cycling Na-Ion Batteries at Low Temperature

Abstract

Sodium-ion batteries stand a chance of enabling fast charging ability and long lifespan while operating at low temperature (low-T). However, sluggish kinetics and aggravated dendrites present two major challenges for anodes to achieve the goal at low-T. Herein, we propose an interlayer confined strategy for tailoring nitrogen terminals on Ti3C2 MXene (Ti3C2-Nfunct) to address these issues. The introduction of nitrogen terminals endows Ti3C2-Nfunct with large interlayer space and charge redistribution, improved conductivity and sufficient adsorption sites for Na+, which improves the possibility of Ti3C2 for accommodating more Na atoms, further enhancing the Na+ storage capability of Ti3C2. As revealed, Ti3C2-Nfunct not only possesses a lower Na-ion diffusion energy barrier and charge transfer activation energy, but also exhibits Na+-solvent co-intercalation behavior to circumvent a high de-solvation energy barrier at low-T. Besides, the solid electrolyte interface dominated by inorganic compounds is more beneficial for the Na+ transfer at the electrode/electrolyte interface. Compared with of the unmodified sample, Ti3C2-Nfunct exhibits a twofold capacity (201 mAh g−1), fast-charging ability (18 min at 80% capacity retention), and great superiority in cycle life (80.9%@5000 cycles) at − 25 °C. When coupling with Na3V2(PO4)2F3 cathode, the Ti3C2-Nfunct//NVPF exhibits high energy density and cycle stability at − 25 °C."Image missing"

Interface Engineering of Fe7S8/FeS2 Heterostructure in situ Encapsulated into Nitrogen-Doped Carbon Nanotubes for High Power Sodium-Ion Batteries

“…6 b) [ 30 , 32 ]. To be more specific, the capacitive contribution at various scan rates can be verified by the following equation [ 56 , 57 ]: where k 1 v represents the contribution from capacitive behaviors, while k 2 v 1/2 corresponds to the contribution from diffusion [ 56 , 57 ]. As can be seen from Fig.…”

“…S17 and S18. Generally, good electrochemical kinetics at high current densities can be obtained from high capacitive contribution, which is beneficial for the rate capability and cycling stability [ 57 ].

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Anionic Activity in Fast-Charging Batteries: Recent Advances, Prospects, and Challenges

“…Recently, Zhenbo Wang and co-workers developed the Nterminal Ti 3 C 2 MXene (Ti 3 C 2 −N) to improve the sodiation kinetics for fast-charging applications. 186 Figure 7b shows that the Na + diffusion energy barrier after N terminal substitution is reduced. Furthermore, Ti 3 C 2 −N exhibits solvent and Na + cointercalation behavior at low temperatures, lowering a large desolvation energy barrier and also forming an inorganicdominated SEI with a decreased charge-transfer barrier (Figure 7c).…”

“…(b) Na + diffusion energy barrier in Ti 3 C 2 O 2 and Ti 3 C 2 O 1.83 N 0.17 . (c) Scheme of the SEI formation and the charge-transfer barriers on Ti 3 C 2 and Ti 3 C 2 –N electrodes, reproduced from ref with permission under a Creative Commons CC-BY License. Copyright 2022 Springer Open.…”

“…Recently, Zhenbo Wang and co-workers developed the N-terminal Ti 3 C 2 MXene (Ti 3 C 2 –N) to improve the sodiation kinetics for fast-charging applications Figure b shows that the Na + diffusion energy barrier after N terminal substitution is reduced.…”