The advances in process engineering, nanotechnology, and materials science gradually enable the potential applications of biomass in novel energy storage technologies such as lithium secondary batteries (LSBs). Of note, biomass-derived materials that range from inorganic multi-dimensional carbons to renewable organic biomolecules or biopolymers can contribute towards “green battery” systems, serving as sustainable battery components. This review offers a comprehensive overview of the fabrication and application of both biomass and biomass-derived materials in LSBs. First, the processing routes of biomass towards different products are considered and described. The corresponding mechanistic understanding of biomass processing is particularly underscored. Classified by the battery components, focused discussions on biomass applied as electrode scaffolds, active cathode/anode materials, binders/additives, and separators/solid-state electrolyte layers in LSBs are systematically provided. The insights from this review demonstrate that biomass has significant potential for the development of high-performance “green battery” systems, which to different extents employ sustainable and green biomass-derived battery components. To accelerate its industrialization, specific attention should be paid to upgrading the processing technologies to maximize biomass utilization with high efficiency and low cost. Meanwhile, we summarize the present limitations over the application of biomass in LSBs and propose potential strategies for revolution. Additionally, we foresee further use of biomaterials to advance LSBs and other alkali-metal secondary batteries. This review comprehensively describes the significance of biomass and biomass-derived materials that have already received some attention and will bring numerous breakthroughs in the battery community. It is intended to attract the broad attention of scientists to this prospective trend of development in “green batteries”.