Single particle electrode microbatteries

Methods are herein described for the assembly and electrochemical characterization of a Li⁺ battery consisting of a single microparticle (ca. 50 μm diam) of LiMn₂O₄ as the cathode, and a single spherical mesocarbon microbead (MCMB) as the anode, using either 1 M LiClO₄ in ethylene carbonate EC/diethyl carbonate DEC mixture (1:1 by volume) or 1 M LiPF₆ in EC/dimethyl carbonate (1:1 by volume) as the electrolyte. Self-discharge curves were recorded by monitoring the potential of the battery as a function of time after charging independently each of the microparticle electrodes to full capacity. The results obtained showed that charge retention is vastly superior for the LiPF₆, compared to LiClO₄-containing electrolyte, in agreement with results published elsewhere using more conventional devices. This behavior has been attributed to the chemical instability of perchlorate ion toward the charged cathode.