TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - The purification is carried out by chemical or thermal means, or a combination of both, or by mechanical means. The Lc and La crystallographic parameters of the graphite are controlled. The graphite may be of the types StratminGraphite, chinese, LacKnife or brazilian. The stages (a) and (b) are effected in controlled conditions so as to provide graphite particles with the following properties :- - an interplanar distance d002(X-ray measurement) between 3.35 Angstrom and 3.38 Angstrom ; - a surface area of 0.4 - 55 m2/g ; and - a purity of 98.5 - 99.99%. Purification is preferably effected chemically in an acid or basic medium ; the acid medium comprises HF, H2SO4, HNO3, HCl or mixtures, and the basic medium is a fluorinated derivative. More preferably, the acid is HF or a fluorinated derivative generating HF, which may be NH4F, NH5F2 or XF (where X is an alkali or alkaline earth metal), or a mixture. Alternatively, the acid medium comprises H2SO4 or HCl as well as a fluorinated derivative, and sufficient HNO3 to enable exfoliation of the graphite. Purification by thermal means can be effected in a furnace at 1000 - 3100degreesC. Mechanical purification is effected by milling to a particle size of 1 - 50 microns followed by separation of impurities by flotation. The prepared graphite particles can be conditioned to form a carbon anode for use in a rechargeable electrochemical battery using an alkali or alkaline earth metal, preferably Li. The anode is prepared by mixing the graphite particles with a minder and solvent and expanding the mixture on a metallic collector. EXAMPLE - A natural graphite of initial particle size 375 microns was milled by an air milling process to a particle size of 10 mu, giving a size distribution D50% of 10.52 microns. The milled graphite was then leached in a bath containing 30% HF at 90degreesC for 180 mins. It was then filtered, washed and dried for 24 hs at 120degreesC. The powder obtained was analyzed by EDX which showed that the major impurity remaining was Ca. The purity of the sample was 99.6%. The graphite was mixed with polyvinylidine fluoride(PVDF) and N-methyl pyrrolidone in a wt. ratio of 90 : 10. The mixture was applied to a copper collector. The graphite electrode thus obtained was vacuum dried at 120degreesC. for 24 hs and mounted in a 2035 type battery(diameter 20 mm, thickness 3.5 mm)A separator Celgard 2300 imbibed with electrolyte 1M LiPF6 + ethylene carbonate/dimethyl carbonate(50/50) was used. Metallic Li was used as the reference and counter-electrode. Electrochemical tests were carried out at ambient temperature and discharge-charge curves obtained between 0 and 2.5 V in C/24. The first coulombic yield was 85%(greater than for commercial graphite used in Li-ion batteries, typically 81%).The reversible capacity was 365 mAh/g , equivalent to x = 0.98 in LixC6, close to the theoretical value of graphite(372 mAh/g).No negative effects were associated with the presence of residual Ca impurities.