Have a look at AVZ if you haven't already. Arguably largest deposit in the world. Only downside is operating in DRC, hence a lot of political risk involved. Otherwise, hope they can replicate the success of GXL and PLS.
Also have a look at N27 (Cobalt company) - not lithium but lithium related as cobalt is one of the major raw materials used in lithium batteries. Cobalt is trading at 9 year highs, almost tripling from lows of early 2o16.