Results of the examination of the electrochemical characteristics of a lithium–manganese spinel in LiBOB–tetraethylene glycol dimethyl ether (tetraglyme) electrolytes as a function of the LiBOB concentration and the cycling and storage temperatures are described. According to the results, the lithium–manganese spinel in electrolytes based on LiBOB–tetraglyme mixtures exhibits a high specific capacity and ability for stable cycling over a wide temperature range. The conductivity of the solutions is governed by the salt concentration, and its temperature dependence is linear in the coordinates of the Vogel–Tamman–Fulcher equation in the temperature range of 10–100°C. The studies were conducted using a lithium anode in 2016 disc cells.