Improved battery performance of Fe-doped LiVPO4F with high capacity and stable cycling

Oxygen-Tuned Na3V2(PO4)2F3–2yO2y (0 ≤ y < 1) as High-Rate Cathode Materials for Rechargeable Sodium Batteries

“…Residual carbon coating is commonly found in Na 3 V 2 (PO 4 ) 2 F 3−2y O 2y (0 ≤ y < 1) due to the excessive carbon during preparation and has great influence on the electrochemical performance. 46 The difference of carbon form and its amount is further investigated by Raman spectroscopy and TGA-DSC analysis. The D band at 1350 cm −1 related to disordered carbon and the G band at 1580 cm −1 related to graphitized carbon are distinctively shown Figure 3c.…”

“…Furthermore, a nonuniform carbon layer with a thickness of about 7.35 nm is also evidently shown in Figure a for Na 3 V 2 (PO 4 ) 2 F 3 ( y = 0), while the thickness of a similar carbon layer in Figure b for Na 3 V 2 (PO 4 ) 2 F 2 O ( y = 0.5) is noticeably decreased to only 3.68 nm. Residual carbon coating is commonly found in Na 3 V 2 (PO 4 ) 2 F 3–2 y O 2 y (0 ≤ y < 1) due to the excessive carbon during preparation and has great influence on the electrochemical performance …”

Ultrafast Laser Drilling of 3D Porous Current Collectors for High-Capacity Electrodes of Rechargeable Batteries

“…The middle panel of Figure 1c shows the preparation of the positive electrodes. 32 Commercial LiFePO 4 was mixed with a polyvinylidene fluoride (PVDF, KYNAR FLEX, >99%) binder and conductive Super-P (Timcal, >99%) (weight ratio: 85/5/10) in N-methyl pyrrolidone (NMP, Aladdin) solution to get a homogeneous slurry, which was then casted onto Al foils with/without laser drilling by an MSK-AFA-III film coater machine (Shenzhen Kejing Co., Ltd.). The so-obtained electrode was dried at 90 °C in vacuum for 12 h and was cut into disc cathodes with the diameter of 15 mm.…”

Effects of Fe doping on the electrochemical performance of LiV1−xFexPO4F/C (x = 0, 0.01, 0.02, 0.04) cathode materials for lithium‐ion batteries

“…Recently, Jiang et al [28] presented a detailed first principle investigation of the stability and electronic property of the LiV 1Àx M x PO 4 F (M = Mn, Fe, Co, and Ni) electrode materials. Their results showed that Fe doping can stabilize the crystal structure of the LiVPO 4 F electrode materials, enhancing the cyclic stability of LiVPO 4 F. Furthermore, Fe ions were used to partially substitute V of LiVPO 4 F. [5] Interestingly, olivine-type LiFePO 4 appears in highly Fe-doped LiVPO 4 F materials, synergistically enhancing the electrochemical performance of the electrode materials. As far as we know, there is no experimental study on Fe ions doping of the LiVPO 4 F/C without any impurity phase.…”

“…With the increase in energy storage requirements, environment-friendly rechargeable lithium-ion batteries with high energy density, long life, high safety, and low cost are required. [1][2][3][4][5][6][7][8][9][10] The phosphate polyanion materials such as olivine-type LiFePO 4 [11,12] and tavorite-type LiVPO 4 F [13][14][15] are considered electroactive materials for lithium-ion batteries. In the LiFePO 4 , the existence of a strong covalent P O bond of (PO 4 ) 3À reduces the redox energy of Fe 3+ /Fe 2+ , which increases the electrode potential relative to Li.…”