Electrochemical properties of P2-Na2/3[Ni1/3Mn2/3]O2 cathode material for sodium ion batteries when cycled in different voltage ranges

Highly Stable Na2/3(Mn0.54Ni0.13Co0.13)O2 Cathode Modified by Atomic Layer Deposition for Sodium‐Ion Batteries

“…In contrast, the MNC electrode cycled between the 2-4.5 Vv oltage range experienced severe capacity decay upon cycling, most likely as ar esult of structuralc hanges and dissolution of active species duringt he C-DC process. [19,20] Despite monotonous capacity fading in the high voltage window of 2-4.5 V, the capacity and cycling performance achieved at 1C is the best reported value for P2-type layered materials used in SIBs. [19,20] It is apparent that the long-term cyclability is an important parameterf or energy-source materials along with ah igh capacity value.…”

“…[19,20] Despite monotonous capacity fading in the high voltage window of 2-4.5 V, the capacity and cycling performance achieved at 1C is the best reported value for P2-type layered materials used in SIBs. [19,20] It is apparent that the long-term cyclability is an important parameterf or energy-source materials along with ah igh capacity value. Nevertheless, the poor cycling stabilitya nd cutoffv oltage limitations of pristine MNC electrode restricted their practical application.…”

“…Wang et al proposedt hat the severe capacity fading observed under elevated voltage conditions is ar esult of crystal structure changes that occur during the charge/discharge (C-DC) process. [19] They also noted that the unstable electrochemical behavior of layered electrode materials cycled at voltages of between 2a nd 4.5 Vr esultsi na ni rreversible phase transformation at voltages greater than 4.3 V. Lu and Dhan also suggested that capacity retention is greatly affected by the P2-O2 phase transformation at voltages above 4.2 V. [20] To stabilize the structure, small-sized cations implementedi nto the host structure have been shown to be successful. [17,18] Although cation doping enhances structural stability, the rate capability of these material is still not adequate for practical applications because of the large particle size, uneven particle shape and distribution, and severe particle agglomeration.…”

Recent Progress in Electrode Materials for Sodium‐Ion Batteries

“…33 Mn 0.67 O 2 with stacking faults was observed when less than 0.33 Na was occupied. [45][46][47] The stable capacity retention was only achieved when the P2-O2 phase transformation was suppressed by limiting the operating voltage to 2.3-4.1 V vs Na + /Na. To further reduce the multiple phase transitions in the Ni/Mn binary P2 cathode and achieve better structural reversibility, the substitution of Li or other transition metal elements such as Fe, Co, and Ti has been performed by many research groups.…”

Insights into the Synergistic Roles of Microwave and Fluorination Treatments towards Enhancing the Cycling Stability of P2-Type Na0.67[Mg0.28Mn0.72]O2Cathode Material for Sodium-Ion Batteries

“…[9][10][11][12][13][14][15][16][17] This is due to the abundance of manganese, importantly P2-type MnO 2 -based materials offer larger tunnels for the intercalation and de-intercalation of the sodium-ion and have been reported to have high capacities. [18][19][20] A sodium-ion layered oxide material crystallizes into either P2-type or O3-type structural phases or mixture of both. In the P2-type phase, the sodium-ion is coordinated in the prismatic sites between the TMO 2 (TM = transition metal) sheets and there are two repeating TMO 2 layers in the unit cell (Fig.…”