With the advent of flexible electronics, flexible lithium‐ion batteries (LIBs) have attracted great attention as a promising power source in the emerging field of flexible and wearable electronic devices. Flexible electrode materials are core components for constructing flexible LIBs. Graphene has many outstanding properties, such as high surface area, excellent electrical conductivity, good mechanical and chemical properties. Therefore, graphene has great potential applications in flexible LIBs. According to the degree of elastic deformation, flexible LIBs can be divided into bendable and stretchable LIBs. In this chapter, we begin with a brief definition of flexible LIBs and the innovative design of stretchable LIBs for applications in this field. This is followed by a detailed overview of the recent progress on bendable electrode materials design based on graphene. Graphene can act as a kind of conductive phase to form composite films with polymer, paper, and cloth. Also graphene can act as bendable current collectors or graphene‐based bendable composite materials in bendable batteries, and graphene fiber‐based electrodes can also act as a component to construct bendable LIBs. Graphene‐based bendable electrode can effectively improve flexibility, power density, and energy density of LIBs, and it is much anticipated in the future. Furthermore, we show characterization of flexible LIBs, including mechanical properties and electrochemical performance. At last, we look forward to the future development in flexible LIBs and believe the great challenge confronting the scientific researchers is to design a flexible batteries with stretchability, self‐healing ability, and high charge rates.