Method for realizing carbon coating of lithium iron phosphate through radio frequency plasma enhanced chemical vapor deposition

[0026] Example 1:

[0027] Weigh 0.078mol each of lithium dihydrogen phosphate, ferrous oxalate and citric acid according to n(Li):n(Fe):n(P):n(citric acid)=1:1:1:1 (by mole), Dissolve citric acid in 250ml of deionized water, dissolve the iron source, lithium source and phosphorus source in 100ml of deionized water respectively, add dropwise to the citric acid solution, stir vigorously at room temperature to form a sol, and evaporate the sol to dryness in a water bath at 80°C The precursor gel was obtained, and the precursor gel was vacuum-dried at 100°C for 8 hours to obtain a dry gel, which was ball milled for 3 hours, and then placed in a tube furnace protected by argon, and pretreated at 300°C for 10 hours to remove CO 2 and H 2 O. Cool to room temperature with the furnace, ball mill for 2h. Calcined at 750°C for 10h in an argon atmosphere (heating rate 2°C·min -1 ), cooling and ball milling to obtain LiFePO 4 / C. The prepared sample LiFePO 4 / C placed in Shenyang

[0028] Example 2

[0029] Weigh lithium hydroxide, ferrous oxalate, ammonium dihydrogen phosphate and citric acid according to n(Li):n(Fe):n(P):n(citric acid)=1:1:1:1 (by mole) 0.078mol each, dissolve citric acid in 250ml deionized water, dissolve iron source, lithium source and phosphorus source in 100ml deionized water respectively, add dropwise to the citric acid solution, stir vigorously at room temperature to form a sol, steam in a water bath at 80°C After drying, a precursor gel was obtained, and the precursor gel was vacuum-dried at 100° C. for 8 hours to obtain a xerogel. Ball milled for 3 hours, placed in an argon-protected tube furnace, and pretreated at 300°C for 7 hours to remove CO 2 and H 2 O. Cool to room temperature with the furnace, ball mill for 2h. Calcined at 650°C for 20h in an argon atmosphere (heating rate 2°C·min -1 ), cooling and ball milling to obtain LiFePO 4 / C. The prepared sample LiFePO 4 / C placed in Shenyang Xinlantian Plasma Enhanced C

[0030] Example 3

[0031] Weigh lithium chloride, ferrous sulfate, ammonium dihydrogen phosphate and citric acid according to n(Li):n(Fe):n(P):n(citric acid)=1:1:1:1 (by mole) Each 0.078mol, citric acid was dissolved in 250ml of deionized water, iron source, lithium source and phosphorus source were dissolved in 100ml of deionized water, respectively, added to the citric acid solution, stirred vigorously at room temperature to form a sol. The precursor gel was obtained after evaporating to dryness in a water bath at 80° C., and dried in vacuum at 100° C. for 8 hours to obtain a xerogel. Ball milled for 3 hours, placed in an argon-protected tube furnace, pretreated at 300°C for 8 hours, to remove CO 2 and H 2 O. Cool to room temperature with the furnace, ball mill for 2h. Calcined at 800 °C for 10 h in an argon atmosphere (heating rate 2 °C min -1 ), cooling and ball milling to obtain LiFePO 4 / C. The prepared sample LiFePO 4 / C placed in Shenyang Xinlantian Plasma Enh