In-situ plasma assisted formation of graphitic nanosheet supported N-doped carbon-coated antisite defectless LiFePO4 as a high-performance cathode material for lithium-ion batteries

A Robust and Scalable N-Doped Carbon Coating Strategy for the High-Performance LiFePO4 Cathode

“…Figure 2b shows the FTIR curves of LFP-0, LFP-1, LFP-2, and LFP-3 and the carbonized PAN, respectively. The peaks at 880−1180 cm −1 could be ascribed to P−O bond antisymmetric stretching vibration, 32 and the peaks at 520−610 cm −1 could be assigned to symmetric and antisymmetric stretching of the vibration of the O−P−O bond. 33 The characteristic absorption peak is found between 1690 and 1500 cm −1 for the -C�C-and -C� N. 34,35 The absorption peak at 2275−2383 cm −1 corresponds to C�O, resulting from CO 2 in the air and the interaction of the graphite layer with trace amounts of oxygen in the environment.…”

Are Fe-Li Antisite Defects Necessarily Detrimental to the Diffusion of Li + in LiFePO4/C?

“…For LFP powders without any Fe-Li defects, the infrared absorption peak of the P-O symmetrical stretching vibration in the phosphate tetrahedron usually appears at 957 cm −1 , which will gradually shift to a higher wavenumber region with the increase of Fe-Li antisite defects. 33,34 Fig. 2 display the FTIR spectra of the four LFP powders, the infrared absorption peak of the P-O symmetrical stretching vibration appears at 958, 966, 978, and 987 cm −1 in the LFP-1, LFP-2, LFP-3, and LFP-4 samples, respectively.…”

Plasma-enabled synthesis and modification of advanced materials for electrochemical energy storage

“…Interestingly, the homogeneous coating of PANI on precursor FePO4 is helpful to control the size of produced LFP particles, which shortens the ion diffusion path, and converts to carbon network after pyrolysis to enhance the electronic conductivity, thereby enhancing the high capacity, rate capability and cyclic stability. In addition, Jiang et al [79] synthesized Fe•Li-antisite-free LFP nanoparticles with nitrogen-doped carbon coating (NC) and graphitic nanosheet support (GNS) using an Ar/H2 plasma-assisted method. As shown in Figure 5b, the precursor (the PANI coated FePO4), LiAc and sucrose are calcined to form LFP@NC, subsequent the mixture of LFP@NC, glucose and FeSO4 is treated with H2/Ar plasma, the plasma discharge not only promotes in-situ formation of GNS on LFP@NC via Fe 0 -catalyzed glucose pyrolysis but also simultaneously removes Fe•Li antisites in LFP, and the Fe•Liantisite-free LFP@NC/GNS is thus obtained.…”