Boosting Pseudo‐capacitive Sodium Storage in Ultrafine Titanium Dioxide by an In‐situ Porous Forming Strategy

Abstract

Due to its properties (stable, affordable and non‐toxic), titanium dioxide (TiO2) has a promising future as electrode material for sodium‐ion batteries (SIBs). Its Na+ insertion/deinsertion mechanism, on the other hand, results in poor electronic conductivity and sluggish ionic diffusivity, leading to rapid capacity fading. Herein, a molten salt method is employed to creat abundant carbon pores framework, being capable of supporting plentiful ultra‐fine TiO2 adhering (U‐TiO2/C). With this unique porous structure of lots of exposed active sites, the U‐TiO2/C composite provides a faster ions transport and volume expansion buffer zone during cycling. As anode for SIBs, the U‐TiO2/C manifests splendid electrochemical performance. Specifically, the U‐TiO2/C electrode delivers a high capacity of 202.7 mAh g−1 after 100 cycles at 0.1 A g−1 and 91.4 mAh g−1 at 1.0 A g−1 after 160 cycles. Even with the increased current density to 10.0 A g−1, the U‐TiO2/C electrode still performs a high capacity of 69.5 mAh g−1 after 2500 cycles. Detailed kinetic analysis has been investigated to quantificationally demonstrate that the surface pseudocapacitive storage behavior plays a dominant role in the enhanced sodium storage.

Synergy of oxygen defects and structural modulation on titanium niobium oxide with a constructed conductive network for high-rate lithium-ion half/full batteries

“…1c, O d -TNO@NC-G, Ti 2p has two obvious binding energy peaks at 459.3 eV (Ti 2p 3/2 ) and 464.8 eV (Ti 2p l/2 ). 38 In Nb 3d from Fig. 1d, Nb 3d 3/2 and 3d 5/2 are located at 210.5 and 207.8 eV, respectively.…”

Electronic Modulation and Structural Engineering of Carbon-Based Anodes for Low-Temperature Lithium-Ion Batteries: A Review

“…Its capacity at -60 °C can be greater than 52% of that at normal temperatures, and at -60 °C it can deliver 679.4 Wh kg -1 of energy density (based on cathode active material), which provides theoretical and experimental design guidelines for logical low-temperature electrolyte design. TiO2 has good potential as an anode for energy storage [32]. Zhang et al designed an optimized TiO2(B) negative electrolyte formula for LiBF4-based LIBs, in which the optimized ratio electrolyte TiO2(B) anode demonstrated a reversible capacity of 240 mAh g -1 at -20 °C (0.1 A g -1 ) [33].…”