| abstract |
An electrochemical secondary element with a non-aqueous electrolyte, whose charge/discharge mechanism is predicated upon the reversible intercalation of active Li+ ions in electrode materials having an open skeletal structure. The positive electrode is essentially a lithium-manganese spinel of the type Li q M x Mn y O z which, in addition to satisfying the expressions 0<x<0.6 and 1.4<y<2.0, can also contain up to 30% of other metals such as Co, in addition to Mn. The negative electrode is based on a carbon product obtained by pyrolysis from organic compounds, and serves as the recipient substance for the Li+ ions. By limiting the Li concentration in the spinel lattice to a range in which the numerical values of the variable q lie between 0 and 1.3, a lithium-poor manganese spinel is obtained. During discharging of the preponderant portion of the secondary element's capacity, the result is that a cell potential greater than 3 volt is obtained, and high cycling stability is also manifested. |