The effects of dual modification on structure and performance of P2-type layered oxide cathode for sodium-ion batteries

Oxide cathodes for sodium‐ion batteries: Designs, challenges, and perspectives

“…C‐PDA prevents the deposition of Na 2 CO 3 /NaOH, which is advantageous to forming the cathode electrolyte interphase layer. Furthermore, the dual‐modification strategy of NaTi 2 (PO 4 ) 3 surface coating and Mg substitution for transition metals was designed to inhibit both the surface side reaction and phase transformation 159 . The NASICON‐type NaTi 2 (PO 4 ) 3 coating layer plays an important role in stabilizing the interface, preventing the impact of HF, and promoting the migration of Na + .…”

“…Furthermore, the dualmodification strategy of NaTi 2 (PO 4 ) 3 surface coating and Mg substitution for transition metals was designed to inhibit both the surface side reaction and phase transformation. 159 The NASICON-type NaTi 2 (PO 4 ) 3 coating layer plays an important role in stabilizing the interface, preventing the impact of HF, and promoting the migration of Na + . In addition, the dual-modification strategy can also restrain particle crack and exfoliation.…”

Probing the charged state of layered positive electrodes in sodium-ion batteries: reaction pathways, stability and opportunities

“…For example, coating the P2-Na 0.67 Ni 0.33 Mn 0.67 O 2 layered oxide stabilizes the interface, while facilitating the migration of sodium ions at the surface. 214 3.4.4 Conductive polymer coatings. Primarily during the extraction of sodium ions from Mn-rich layered oxides (i.e.…”

“…218 The irreversible consumption of sodium ions can pose a signicant problem for P2-type layered oxide structures which are inherently sodium decient. On top of methods discussed earlier, such as electrolyte optimization (Section 3.3) and surface modications (Section 3.4), the addition of sacricial sodiation reagents to the anode and/or cathode material, such as sodium powder, 214 NaN 3 , 219 Na 3 P, 220 223 has been reported to compensate for the sodium deciency and signicantly improve the performance of sodium ion full cells. For example, Guo et al showed that the capacity retention in a full cell based on a hard carbon negative electrode and a P2-Na 2/3 Ni 1/3 Mn 1/3 Ti 1/3 O 2 positive electrode can be increased from 63% to 85% aer 200 cycles at 0.2C with a voltage window of 2.0-4.3 V by the addition of Na 2 C 2 O 4 .…”

Manipulating Stable Layered P2‐Type Cathode via a Co‐Substitution Strategy for High Performance Sodium Ion Batteries

“…Accordingly, the redox peaks at low-voltage region (below 3 V) are related to the reversible reaction of Mn 3+ /Mn 4+ couple, while the two peaks at about 3.25 and 3.65 V are attributed to the redox process of Ni 2+ /Ni 3+ and Ni 3+ /Ni 4+ , respectively. [38,48,49] Moreover, the strong peak above 4.25V in the first cycle is possibly assigned to the formation of solid electrolyte interface (SEI) film, and the highly overlapped curves of the remaining cycles elucidate the good structural stability of the cathode material. [40] Compared with the NaLiZNMO-180, the CV curves of the unsubstituted NaNMO sample show more obvious multiple redox peaks.…”