The formation of dendrites on the surface of the lithium anode has long delayed its exploitation. We recall the different morphologies of these surface inhomogeneities and the models that can now explain their formation. Part of this chapter is devoted to the strategies used to overcome dendritic formation. Another difficulty is the high reactivity of lithium. This makes it difficult for lithium to be compatible with the liquid electrolytesLiquid electrolytes used in lithium-ion batteries. This is a disadvantage because the liquid electrolyteLiquid electrolytes has a very high ionic conductivity, which is difficult to achieve with solid electrolytes. However, progress has been made over the last decade to significantly improve the cycle lifeCycle life of lithium batteries with liquid electrolytesLiquid electrolytes through the appropriate choice of lithium salts, solvents, additivesAdditivessolvent and the formation ofSolid-electrolyte interface (SEI)additives artificial solid-electrolyte interfaces. These are reviewed in this chapter. An entire section is also devoted to gel polymer electrolytesGel polymer electrolytes, which have recently produced remarkable results. Due to their importance, solid ceramic electrolytes are reviewed and discussed in a separate chapter. Morphology also plays an important role, and a section is devoted to the choice of skeletons that allow lithium to be anchored on three-dimensional current collectorsCurrent collectors. The last section discusses the state of the art of lithium-metalBatterieslithium-metal batteries.