Gadolinium/chloride co-doping of lithium vanadium phosphate cathodes for lithium-ion batteries

Improved Na storage performance of Na3V2(PO4)3 cathode material for sodium-ion batteries by K-Cl co-doping

“…Table 1 shows that the lattice parameters of a, b, c, and V of the K + and Cl − co-doped NVP are larger than those of the undoped one. The reason for this could be attributed to fact that the radius of K + (1.38 Å) is larger than the Na + (1.02 Å) and the Cl − influence on the electronic cloud of PO 4 3− [29,33], which could broaden the Na + channel. Furthermore, there are no diffraction peaks corresponding to the carbon coating in the XRD patterns of the four groups of composite materials; this is related to the carbon in the material that exists in an amorphous form, or the carbon content is relatively small .…”

“…110.4 at 0.2 C Na 2.90 K 0.10 V 2 (PO 4 ) 3 /C 81.7 at 5 C - [33] 105 at 0.2 C Na 2.79 K 0.07 Ca 0.07 V 2 (PO 4 ) 3 /C 88.6 at 5 C 91% at 1 C after 50 cycles [41] 104 at 0.2 C Na 3 V 1.7 Mn 0.3 (PO 4 ) 3 /C 92 at 2 C - [42] 107.9 at 0. This is due to the synergy of K + and Cl − , which can generate more Na vacancies and expand the diffusion channels, thereby improving the rate performance of NVP [29,31,35]. It is worth noting that the amount of K + and Cl − doping also has a non-negligible impact on the NVP rate performance.…”

“…In addition, doping with cations and anions could be further improved due to the synergy of cations and anions [28]. Chen et al [29] synthesized the Gd 3+ and Cl − co-doped Li 3 V 2 (PO 4 ) 3 via a rheological phase method reaction. Thanks to the effects of the co-doping strategy, the sample delivered much higher discharge capacity, which also proved that this strategy did not destroy the electrochemical performance.…”

The Effect of Gadolinium Ion Doping on Electronic Conductivity of LiFePO₄/C

“…Theoretical studies predict that doping with transition metals can increase capacity, while doping with nontransition metals leads to increased potential [10]. Doping cations can modify the distribution of electrons on the LiFePO4 surface thereby increasing reactivity and conductivity, whereas anion doping increases performance at broad current densities [11].…”