Advanced Methodology for Optimization of Comprehensive Properties in LiFePO4/C Cathodes via Doping with Diverse Aluminum Sources

Description

Lithium iron phosphate (LiFePO4, LFP) remains one of the most commercially important cathode materials for lithium-ion batteries, and aluminum (Al) doping combined with carbon coating is a widely adopted strategy to improve its electrochemical performance. However, the combined effect of different Al sources and sintering processes on the final structural and electrochemical properties of LFP/C composites has not been systematically compared in a controlled experimental framework, and the lack of open, standardized datasets for this system hinders reproducible research and the development of data-driven material optimization. This dataset presents a complete set of systematically collected structural and electrochemical data for Al-doped LFP/C materials, generated from a controlled experimental design with two variables: Al source (Al2O3, Al(OH)3, AlPO4) and sintering process (static sintering in a tube furnace, dynamic sintering in a fluidized bed). The dataset contains all core quantitative data supporting the conclusions of our associated research: it includes Rietveld refinement results of X-ray diffraction (XRD) patterns that confirm Al doping into the LFP lattice, resulting in varied cell parameters across different samples; the ID/IG ratio calculated from Raman spectra that reflects the graphitization degree of the carbon coating; full first-cycle charge-discharge data, rate performance data, and long-term cycling capacity data for all samples; and raw Nyquist plot data from electrochemical impedance spectroscopy (EIS) along with calculated apparent lithium-ion diffusion coefficients. Notably, the dataset shows that Al source type and sintering process jointly influence the degree of Al incorporation, interfacial impedance, and final electrochemical performance, with Al(OH)3 as the Al source and dynamic fluidized bed sintering delivering the best overall rate and cycling performance. This dataset can be used directly for: (1) cross-study comparison of Al-doped LFP performance to verify process-structure-property relationships; (2) training and validation of machine learning models for LFP material performance prediction; (3) benchmarking new characterization or data analysis methods for battery cathode materials; and (4) reproducing our original results to enable further meta-analysis of LFP modification strategies. All data files are provided in open, editable XLSX format with clear sheet and column labels to facilitate direct use by other researchers.

Steps to reproduce

(1) Sample Synthesis: The Li2CO3, FePO4, and Al sources were mixed in deionized water with 8 wt.% glucose in a certain proportion. Al(OH)3, Al2O3, and AlPO4 served as the Al sources. In this case, the molar ratio of Li to Fe was 1.007:1. The amount of Al dopant used resulted in an Al content of 2000 ppm relative to the total mass of Li2CO3, FePO4, and glucose. The slurry was spray-dried to obtain precursor particles with controlled size distribution, which were then processed via two sintering routes: (2.1) Static sintering: Precursor particles were placed in an alumina crucible, sintered at 800 °C for 1 h under a flowing argon atmosphere in a tube furnace (heating rate: 5 °C/min), then cooled naturally to room temperature. (2.2) Dynamic sintering: Precursor particles were loaded into a fluidized bed reactor, sintered at 800 °C for 1 h under flowing argon with continuous rotation, then cooled in-situ. (3) Structural Characterization: (3.1) XRD: Powder X-ray diffraction patterns were collected on a Bruker D8 ADVANCE diffractometer (Cu Kα radiation) over a 2θ range of 10–90° with a step size of 0.02°. Rietveld refinement was performed using GSAS II software to obtain lattice parameters and reliability factors, which are compiled in 01_XRD Rietveld Refinement.xlsx. (3.2) Raman: Raman spectra were recorded on a Horiba Jobin Yvon LabRAM HR Evolution spectrometer with a 532 nm excitation laser. The D-band and G-band peak intensities were integrated, and the ID/IG ratio was calculated, as listed in 02_Raman Spectra_ID IG Ratio.xlsx. (4) Electrochemical Testing: All samples were fabricated into CR2032 coin-type half-cells for testing: 79 wt.% active material, 11 wt.% super P carbon black, and 10 wt.% polyvinylidene fluoride (PVDF) binder were mixed in N-methyl-2-pyrrolidone (NMP) to form a homogeneous slurry, which was cast onto an aluminum foil current collector, dried at 100 °C for 3 h under vacuum, and punched into 16 mm diameter discs. Cells were assembled using lithium metal as the anode, 1 M LiPF6 in DMC/EC/EMC (1:1:1 v/v/v) as the electrolyte, and a polypropylene separator. (4.1) Galvanostatic charge-discharge (GCD) testing was performed on a LAND battery testing system in a voltage range of 2.35–3.85 V (vs Li/Li⁺) at 25 °C. First-cycle specific capacity, rate performance (from 0.1C to 5C) and long-term cycling performance (100 cycles at 1C) data are recorded in the three XLSX files under the 03_Electrochemical Performance group. (4.2) Electrochemical impedance spectroscopy (EIS) was measured on a Princeton Applied Research PARSTAT 4000A electrochemical workstation in a frequency range of 100 kHz to 10 mHz with an AC amplitude of 5 mV. Raw real impedance and imaginary impedance data for all samples are stored in 04_EIS Spectra.xlsx. The apparent lithium-ion diffusion coefficient (DLi) was calculated from the linear fit of the low-frequency region of the EIS data, and the results are compiled in 04_EIS Spectra_Calculation of DLi.xlsx.

Institutions

• Ordos Laboratory

  Inner Mongolia, Ordos

Categories

Funders

• Development of large-scale production technology and equipment (platform construction) for lithium iron phosphate used in lithium batteries by fluidized bed method

  Grant ID: ordoslabpt202501
• Key technologies and industrial verification for large-scale production of silicon-carbon anode powder in fluidized bed reactors

  Grant ID: Ordoslab-kjzc-202504

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