Investigation the sodium storage kinetics of H_1.07Ti_1.73O₄@rGO composites for high rate and long cycle performance

Abstract

Insertion type material has been attracted plenty of attentions as the anode of sodium ion batteries (SIBs) due to the low volume change induced long cycle stability. H 1.07 Ti 1.73 O 4 (HTO), a two-dimensional layered material, is a new insertion type anode material for SIBs reported in this study. Layered HTO composites were decorated with rGO nanosheets via an electrostatic assembly method followed by hydrothermal treatment. When adapted as the anode material of SIBs, HTO@rGO composite exhibits an enhanced sodium ion storage behavior, including high rate capability and long cycle stability. It can deliver high capacities of 142.8 and 66.7 mA h g −1 at 100 and 10 000 mA g −1 , respectively. Moreover, it can keep a capacity of 75.1 mA h g −1 at 5 A g −1 after even 5000 cycles, corresponding to a high capacity retention of 70.8% (0.0058% capacity decay per cycle). HTO exhibits a small volume expansion of 19.6% by in-situ transmission electron microscopy (in-situ TEM). The diffusion coefficient of sodium ions is increased from 1.77 × 10 −14 cm 2 s −1 in HTO composites to 4.80 × 10 −14 cm 2 s −1 in HTO@rGO composites. Our designed and synthesized HTO@rGO provides a new route for high rate and long cycle stable SIBs anode materials.

Rational design of Fe-doped K0.8Ti1.73Li0.27O4@rGO as a high-rate and long-cycle-life anode for lithium-ion batteries

“…In all the CV curves for KLTO, Fe 2 -KLTO, and Fe 2 -KLTO@rGO, a pair of reversible redox peaks at about 1.0/0.7 V is due to Li + extraction/insertion. This indicates the intercalation reaction and is consistent with the previous report [36]. The capacity loss at around 0.4 V can be attributed to the formation of a solid electrolyte interphase (SEI) film [52].…”

“…It is reported that the improved capacity of amorphous carbon-coated KLTO was 120 mAh g −1 at 20 mA g −1 without capacity loss after 250 cycles [27]. Compared to amorphous carbon modification, 2D rGO nanosheets are proved to preferably prevent agglomeration of titanate nanomaterials to a certain extent and further improve the surface kinetics of lepidocrocite-type H 1.07 Ti 1.73 O 4 in SIBs [35][36][37]. However, few studies have investigated the electrochemical performance of KLTO in LIBs after rGO modification.…”

In Situ Transmission Electron Microscopy for Sodium‐Ion Batteries

“…FeF 2 , [14] CF x , [15] Se [16] Anode materials Insertion Expanded graphite (EG), [17] Hard carbon, [18] Soft carbon, [19] Carbon nanofibers (CNFs), [20] CNFs network, [21] Multi-walled carbon nanotubes (MWCNTs), [22] Nitrogen-doped carbon nanotubes (NCTs), [23] Reduced graphene oxide (rGO), [24] Phosphorus-doped graphene (GP), [25] Nitrogen-doped graphene (GN), [25] TiO 2 , [26] H 1.07 Ti 1.73 O 4 [27] Alloying Sn, [28] Bi, [29] Si, [30] Ge, [31] Sb, [32] Red P, [33] Black P, [34] 𝛽-Zn 4 Sb 3 , [35] SnSb [36] Conversion CuO, [37] CuO/C, [38] CuO/Au, [39] NiO, [40] NiCo 2 O 4 , [41] Co 9 S 8 , [42] FeS 2 , [43] Fe 0 . 95 S 1.05 , [44] Cu 2 S, [45] Ni 3 S 2 , [46] FeP [47] Insertion-Conversion Co 3 O 4 , [48] MnO 2 [49] MoO 3 [50] MoS 2 [51] CuS, [52] TiS 2 , [53] WS 2 , [54] ReS 2 , [55] WSe 2 , [56] NH 4 V 4 O 10 [57] Conversion-Alloying Sb 2 O 3 ,…”