A Lithium-7 nucleus and a proton come together under conditions of high temperature and pressure (as in a fusion reactor or stellar environment).
As said the piloting work of Lipinisky did show tat the optimal energy for 7-Li-p fusion is 100eV this is still pretty hot but definitely not solar and not high energy plasma.
Principally there is no Coulomb barrier as atoms are neutral. E.g. H*-H* can freely penetrate nuclear orbits like a neutron. What is needed is the stripping off, of the first 7-Li electron and a polarization of the spin-paired second electrons (S2) what may induce a H*-7Li bond that will collapse to 2 alphas. The main problem is that you need pure isotopes, what the US army currently still will not allow you to have...
With mixed 6-Li/7-Li no polarization will happen at least not enough for a high COP.