Modified graphite particles obtained from graphite or based on graphite, the said particles having impurities in their internal structure and having on the surface a low, even nil, rate of an impurity or several impurities. In addition, these particles have at least one of the following characteristics: a tab density between 0.3 and 1.5 g/cc; a potatolike shape; and a granulometric dispersion such that the D90/D10 ratio varies between 2 and 5 and the particles have a size between 1 and 50 μm. These particles can be used for fuel cells, electrochemical generators, or as moisture absorbers and/or oxygen absorbers and they have important electrochemical properties. The electrochemical cells and batteries thus obtained are stable and safe.