  We examine production of Li on the surface of a low-mass secondary in a black
hole soft X-ray transient (BHSXT) through the spallation of CNO nuclei by
neutrons which are ejected from a hot (> 10 MeV) advection-dominated accretion
flow (ADAF) around the black hole. Using updated binary parameters, cross
sections of neutron-induced spallation reactions, and mass accretion rates in
ADAF derived from the spectrum fitting of multi-wavelength observations of
quiescent BHSXTs, we obtain the equilibrium abundances of Li by equating the
production rate of Li and the mass transfer rate through accretion to the black
hole. The resulting abundances are found to be in good agreement with the
observed values in seven BHSXTs. We note that the abundances vary in a
timescale longer than a few months in our model. Moreover, the isotopic ratio
Li6/Li7 is calculated to be about 0.7--0.8 on the secondaries, which is much
higher than the ratio measured in meteorites. Detection of such a high value is
favorable to the production of Li via spallation and the existence of a hot
accretion flow, rather than an accretion disk corona system in quiescent BHSXT.
