Improved cycle and air stability of P3-Na0.65Mn0.75Ni0.25O2 electrode for sodium-ion batteries coated with metal phosphates

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

“…197,198 Upon exposure to air, the metal phosphate coated P3-Na 0.65 Mn 0.75 -Ni 0.25 O 2 material was found to retain high electrochemical activity. 197 While the coating led to enhanced air stability and cycling longevity, a slight decrease of discharge capacity for the coated materials was observed. In comparison to metal oxides and metal phosphates, NASICON-type titanium phosphate coating layers such as NaTi 2 (PO 4 ) 3 have the added advantage of being good sodium ion conductors, thus leading to faster sodium diffusion kinetics at the CEI.…”

“…Metal phosphate protective layers including AlPO 4 , Mg 3 (PO 4 ) 2 and NaPO 3 can effectively suppress irreversible oxidation of oxygen in the high voltage region while inhibiting the loss of lattice oxygen. 197,198 Upon exposure to air, the metal phosphate coated P3-Na 0.65 Mn 0.75 -Ni 0.25 O 2 material was found to retain high electrochemical activity. 197 While the coating led to enhanced air stability and cycling longevity, a slight decrease of discharge capacity for the coated materials was observed.…”

“…[193][194][195][196] However, the interplay between coatings and anion redox reactions in Na layered oxides is relatively unexplored and the mechanism is not well understood. 197,198 3.4.1 Carbon coatings. To prevent moisture uptake, mitigate side reactions, and decrease polarization, a carbon coating can be applied to prevent direct contact between the electrode material and external environment.…”

An advanced low-cost cathode composed of graphene-coated Na2.4Fe1.8(SO4)3 nanograins in a 3D graphene network for ultra-stable sodium storage

“…During the past decade, enormous efforts have been made to peruse different kinds of electrode materials for SIBs [5][6][7][8][9][10][11]. Specifically, for the cathodes, transition metal oxides [12][13][14][15][16][17][18], phosphates [19][20][21][22][23][24][25][26][27][28], and ferrocyanides [29,30], have demonstrated decent electrochemical properties. From the structural and economic aspects, Fe-based polyanions should be a favorable choice for electrode materials, owing to the combination of the cost-effective and environmental-friendly of Fe element, with the robust and stable structure of polyanion frameworks essential for prolonged cycling and safety issues [31,32].…”

Surface Engineering Suppresses the Failure of Biphasic Sodium Layered Cathode for High Performance Sodium‐Ion Batteries

“…[ 15,16 ] However, some researchers noted that P3‐Na 2/3 Ni 1/3 Mn 2/3 O 2 has faster Na + diffusion rate and higher discharge capacity. [ 17–19 ] Although individual materials with single‐phase structure possess certain advantages in specific electrochemical applications, they are also restricted by intrinsic deficiencies in other aspects due to their specific structure. To integrate the advantages of different phases and overcome the inherent defects of each single phase, the construction of a multiphase structure is considered to be an effective solution for producing high‐performance SIBs cathode materials.…”