by way of comparison the rhombohedral phase was enriched using a known process starting from a graphite h containing less than 5 of rhombohedral phase graphite h was ground in an impeller breaker for a minimum period of 15 minutes a powdered carbon containing material f was thus obtained which contained 14 of rhombohedral phase anodes were produced from carbon containing graphite containing materials k l h and f as described for example 1 electrochemical cells analogous to those described in example 1 and shown in fig6 were made up each cell included one of the anodes produced above the specific area of the material was first evaluated as described in example 1 by measuring the capacitance of the double layer this was followed by electrochemical cycling of the assembled cells the first cycle is shown in fig1 for materials k curves 11 12 and l curves 13 14 this was carried out initially by a first intercalation of lithium in the anode curves 11 and 13 under conditions of 40 ma g of carbon until a potential of 0 volts relative to lithium li li was reached thereafter the lithium was de intercalated curves 12 and 14 under the same conditions until a potential of 2 volts was reached the difference in capacity u03b4 between these two cycling steps corresponds to the loss of capacity due to passivation of the anode passivation capacity the results obtained appear in table iii below table iii______________________________________ rhombohedral double layer passivation phase capacitance capacity u03b4material mf g mah g ______________________________________k lt 5 245 505l 13 256 420h lt 5 400 80f 14 1500 160______________________________________ it can be seen that producing carbon containing material 1 using the.