Purifying the Phase of NaTi₂(PO₄)₃ for Enhanced Na⁺ Storage Properties

Abstract

Sodium-ion batteries (SIBs) are increasingly on demand owning to their prospect as an inexpensive alternative to Li-ion batteries. However, designing electrode materials with satisfactory rate capacity performance requires high electron transport and Na+ conductivity, which is extremely challenging. Herein, we report a hexadecylamine (HDA)-mediated synthesis of NaTi2(PO4)3 (NTP) electrodes via one-step solvothermal process. The addition of HDA material (1) enables the formation of a carbon coating that improves the electron conductivity and (2) importantly serves as a structure-directing agent reducing the NTP-impurity phases in which the transport of Na+ ions are sluggish. As a result, the synthesized NTP anode delivers superior rate of capacity retention of 77.8% under the 100-fold increase in current densities. Moreover, outstanding specific capacity of 117.9 mAh g–1 at 0.5 C and capacity retention of 88.6% after 1500 cycles at 1 C can be obtained. The findings of this work provide new opportunity to design SIBs electrodes with superior electrical and ionic conductivity.

Self-Supported NaTi2(PO4)3 Nanorod Arrays: Balancing Na+ and Electron Kinetics via Optimized Carbon Coating for High-Power Sodium-Ion Capacitor

“…27 The Ti 2p spectra of the NTP@C NR sample (Figure 3e) showed Ti 2p 1/2 at 465.8 eV and Ti 2p 3/2 at 460.5 eV, which matched well with Ti 4+ peaks in NTP. 30,31,34 Figure 3f shows the C 1s spectrum, which were located at 284.8 eV (C−C) and 289 eV (C−O). 25 The electrochemical performances of the NTP NR, NTP@ C NC, L-NTP@C NR, NTP@C NR, and H-NTP@C NR electrodes were tested by half-cells (voltage window: 1.4−3 V) for SIBs.…”

Na 2 TiV ( PO 4 ) 3 @C composite with excellent Na‐storage performance based on a solid‐state polymer electrolyte membrane

“…00‐053‐0018 of Na 3 V 2 (PO 4 ) 3 and No. 33‐1296 of NaTi 2 (PO 4 ) 3 ), indicating the as‐prepared product is isostructural to these phases 47,48 . Moreover, it is obvious that the as‐prepared sample displays a distinct peak between 20° and 35°, which indicates the presence of carbon in NTVP@C 49 .…”

“…33-1296 of NaTi 2 (PO 4 ) 3 ), indicating the asprepared product is isostructural to these phases. 47,48 Moreover, it is obvious that the as-prepared sample displays a distinct peak between 20 and 35 , which indicates the presence of carbon in NTVP@C. 49 There is no other trace of crystalline impurities and intermediate phases detected in the sample, which confirms high purity of the product.…”

All Binder-Free Electrodes for High-Performance Wearable Aqueous Rechargeable Sodium-Ion Batteries

“…Despite these advantages, the rate performance of NTP is limited by its poor electronic conductivity. High-temperature carbon coating, adopted in most of the previously reported studies, has been regarded as an effective method to overcome this issue [ 40 , 41 ]. Unfortunately, this method is complex and involves harsh conditions.…”

“…Among various anode materials for SIBs, NTP, as a member of the NASICON family with an open framework and remarkable ionic conductivity, is considered as one of the most promising anode materials for SIBs because of its low cost and high theoretical capacity [40][41][42][43][44][45]. Despite these advantages, 1 3 the rate performance of NTP is limited by its poor electronic conductivity.…”