Do supernovae produce an appreciable amount of lithium? David Z's answer to this question got me wondering - is any appreciable amount of lithium produced as the result of a supernova explosion, either by fusion (which seems unlikely to me, but I don't have great intuition for this), or by the decay of unstable species produced by the supernova? If so, what decay chains end with lithium?
 A: Lithium and other light elements (e.g. beryllium) can be formed indirectly from supernovae via cosmic ray spallation, a process where protons and neutrons are ejected when a cosmic ray collides with another atom. The nuclei can then become new elements. Nakamura & Shigeyama (2004) were able to calculate yields for 6Li, 7Li, and isotopes of Beryllium and boron from supernovae SN 1998bw, SN 2002ap, and SN 1994I. The total yield of 6Li and 7Li from each of the supernovae were 5.67$\times$10-7 M$_{\odot}$, 0.1981$\times$10-7 M$_{\odot}$, and 0.0130$\times$10-7 M$_{\odot}$, respectfully.
More specifically, the formula for indirect yield (rather, change in the number of the element over the change in time) is
$$\frac{dN_l}{dt}=n_j\int_{\epsilon_{\text{Min}}}^{\epsilon_{\text{max}}}\sigma^l_{i,j}\frac{F_i(\epsilon,t)}{A_im_p}v_i(\epsilon)d\epsilon$$
via the $i+j\to l+\cdots$ reaction, where $n_j$ is number density, $\sigma^l_{i,j}$ is the reaction cross-section, and $A_i$ is the mass number. $F_i(t,\epsilon)$ is a transfer equation.
Much earlier, Truran (1973) cited Meneguzzi et al. (1971) in stating that galactic cosmic ray spallation can account for only 10% of the 7Li abundance, based on measurements in the Solar System. It is thought that supernovae were an important source of these, but they are but no means the only one. More recent estimates (e.g. Prantzos (2010)) set the upper bound at 30% (courtesy of Rob Jeffries).
