A simple pre-sodiation strategy to improve the performance and energy density of sodium ion batteries with Na₄V₂(PO₄)₃ as the cathode material

Abstract

Sodium-ion batteries are considered as a surrogate to conventional lithium-ion batteries for the commercial sector. One of the most auspicious anode materials for sodium-ion batteries is hard carbon. However, its...

Crystal Structure of the Intermediate Na2V2(PO4)3 Phase and Electrochemical Reaction Mechanisms in NaxV2(PO4)3 (1 ≤ x ≤ 4) System

“…SEM images of the Na3V2(PO4)3 powder (Figure S1) show that the particles have no particular shapes as similar to other studies. [11][12][13][17][18][19][20][21][22] However, relatively large agglomerates ranging from few microns to several tenths of microns were found with the primary particles in the size of a few hundreds of nanometers. The powder is carbon-coated on the surface, ca.…”

“…8,9,[14][15][16] It is well known that two Na + ions can be reversibly electrochemically extracted from a Na3V2(PO4)3 electrode, through a voltage-composition "plateau" at ~3.4 V (vs. Na + /Na) utilizing the V 4+/3+ redox couple (with a theoretical capacity of 117.6 mAh/g). 13,[17][18][19][20][21][22] The reaction has been described by many authors as a mechanism of two-phase reaction between Na3V2 3+ (PO4)3 and Na1V2 4+ (PO4)3. 13,[17][18][19][20][21][22] Additionally, one Na + ion can be inserted into Na3V2(PO4)3 at ~1.6 V (vs. Na + /Na) through the V 3+/2+ redox couple towards the Na4V2(PO4)3 composition (theoretical capacity of 58.8 mAh/g).…”

“…13,[17][18][19][20][21][22] The reaction has been described by many authors as a mechanism of two-phase reaction between Na3V2 3+ (PO4)3 and Na1V2 4+ (PO4)3. 13,[17][18][19][20][21][22] Additionally, one Na + ion can be inserted into Na3V2(PO4)3 at ~1.6 V (vs. Na + /Na) through the V 3+/2+ redox couple towards the Na4V2(PO4)3 composition (theoretical capacity of 58.8 mAh/g). 18,19,[22][23][24][25][26][27] Recently, Zakharkin et al 20 noticed the signature of an intermediate Na2V2(PO4)3 phase, which involves the V 4+/3+ redox couple.…”

“…13,[17][18][19][20][21][22] Additionally, one Na + ion can be inserted into Na3V2(PO4)3 at ~1.6 V (vs. Na + /Na) through the V 3+/2+ redox couple towards the Na4V2(PO4)3 composition (theoretical capacity of 58.8 mAh/g). 18,19,[22][23][24][25][26][27] Recently, Zakharkin et al 20 noticed the signature of an intermediate Na2V2(PO4)3 phase, which involves the V 4+/3+ redox couple. Nevertheless, no structural information on the intermediate phase was provided.…”

Chemical Preintercalation of H2V3O8‐reduced Graphene Oxide Composites for Improved Na‐ and Li‐ion Battery Cathodes

“…In this context, Na is a promising alternative to lithium due to its low redox potential of −2.71 V vs. SHE and its easy accessibility, since it is an abundant element in the earth's crust [2,7,8] . Perveen et al.…”