We report a neutron diffraction experiment on liquid ⁷Li_xSi_1-x alloys (x=0.80, 0.65 and 0.57) just above the liquidus and on ⁷Li₅₇Si₄₃ at about 200 K above the liquidus. We obtained absolutely normalized and fully corrected structure factors and radial distribution functions. Which provide indications for the occurrence of chemical ordering in all three alloys. We have analysed the data by fitting models to the structure factor and to the radial distribution function, and by using the reverse Monte Carlo (RMC) method. We find strong indications for the presence of covalently bonded Si in liquid Li₆₅Si₃₅ and Li₅₇Si₄₃. The Si-Si coordination number Z_SiSi varies from about 1.5 in Li₆₅Si₃₅ to about 2 in Li₅₇Si₄₃. For c_Si>0.2, Si forms poly-anions ranging from dumbbells to large three-dimensional structures. Z_SiSi in Li₅₇Si₄₃ is not strongly temperature dependent and consequently the poly-anions are fairly stable. Covalently bonded Si is absent in liquid Li₈₀Si₂₀. The RMC modelling indicates that individual Si atoms are well separated. This suggests that the covalent character of Si in the Si-rich alloys (Li₆₅Si₃₅ and Li₅₇Si₄₃) changes to a more ionic character in Li₈₀Si₂₀.