Graphenehas attracted increasing interest in lithium storagebecause of the significant improvement in electrochemical performance of graphene-based electrode materials.Here,the three key issues related to the applications of graphene materials in lithium batteries will be discussed: how to prepare graphene materials with controlled structures and in a large scale,how to use graphenematerials in lithium batteries,and what are the roles of graphene materials in lithium batteries.First,we developed several methods to realize the large-scale production of graphene materials with controlled structures including reduced graphene oxide(rGO),high-quality few-layer graphene,and three-dimensional graphene network materials.Second,we designed and fabricated a series of rGO-based high-performance composite electrode materials for lithium ion batteries.Synergistic effects between rGO and electrode materials and the beneficial roles ofrGO in composite electrodes were found.It was demonstrated that,when the composites were usedas electrode materials for lithium storage,compared to their individual constituents,rGO composites with unique structures such as anchoring,wrapping,encapsulating,sandwiching,buffering,layering and mixingshowed a significant improvement in theirelectrochemical properties such as high capacity,high rate capability and excellent cyclingstability.The roles of rGOwerefound mainly to form a conductive network,and to form an oxygen bridge with the electrode materials to anchor and trap electrode materials,and to increase Li + diffusion rate and Li + reaction kinetics.Third,we found that the rGO can also be used to improve the performance of lithium sulfur batteries because of the formation of strong bonds between the oxygen-containing groups in rGO and polysulfide,preventing the dissolution of polysulfide into the electrolyte.Finally,we demonstrated the use of high-quality few-layer graphene and three-dimensional graphene network materials in lithium batteries.