LAUSR

DOI: 10.1002/aenm.201901774 supercapacitors, fuel cells, and so forth. They are typically composed of a cathode and an anode coated on metallic current collectors, an electrolyte allowing ion transport, and a separator insulating the two electrodes. Among the various energy storage systems, rechargeable batteries such as lithium ion batteries (LIBs) have gained great commercialization success and have been applied as power supplies in many personal and industrial areas. Unfortunately, state-of-the-art LIBs using an Li-compound cathode (e.g., LiCoO2) and a graphite anode approach their theoretical energy limits, making them barely sufficient to meet high-demanding needs for such as long-range electric vehicles.[2,3] Therefore, advanced LIBs with innovative high-capacity electrodes, e.g., metal oxides, silicon, etc. are of great interest, which are able to generate much higher energy density.[4] More significantly, nextgeneration batteries, “beyond LIBs” (e.g., lithium–sulfur (Li–S) and lithium–oxygen (Li–O2) batteries, etc.), have emerged as a type of attractive energy storage devices, which feature ultrahigh energy density tremendously exceeding today’s LIBs.[5,6] In short, developing advanced high-energy Libased batteries (i.e., LIBs and beyond “LIBs”) is of great significance for satisfying the needs by booming expansion of power supply markets. For realization of high-energy Li-based batteries, in recent decades, advanced high-capacity electrodes have received considerable attention, which enable to store much more energy than currently used conventional electrodes. Namely, silicon anode is well known by its ultrahigh theoretical capacity of 4200 mA h g−1[7] compared with 372 mA h g−1 for graphite anode.[8] Meanwhile, various high-capacity anodes based on metal oxides such as Fe3O4, TiO2, Co3O4, etc.,[9–11] and highcapacity cathodes (e.g., Li-rich, Ni-rich cathodes, etc.[12,13]) have been widely studied for developing high-energy LIBs. Besides the high-capacity cathodes, high-voltage cathodes such as spinel LiMn2O4 and its high-voltage derivatives have become more and more prevailing today.[14,15] Furthermore, rechargeable Li metal batteries directly using Li metal as the anode are emerging as very promising battery systems, which are also known as “beyond LIBs.”[16,17] It is noted that Li metal when used as an anode, exhibits remarkable advantages of ultrahigh theoretical capacity (3860 mA h g−1), the lowest redox potential (−3.04 V vs the standard hydrogen electrode) and low bulk Developing high-performance batteries through applying renewable resources is of great significance for meeting ever-growing energy demands and sustainability requirements. Biomaterials have overwhelming advantages in material abundance, environmental benignity, low cost, and more importantly, multifunctionalities from structural and compositional diversity. Therefore, significant and fruitful research on exploiting various natural biomaterials (e.g., soy protein, chitosan, cellulose, fungus, etc.) for boosting high-energy lithium-based batteries by means of making or modifying critical battery components (e.g., electrode, electrolyte, and separator) are reported. In this review, the recent advances and main strategies for adopting biomaterials in electrode, electrolyte, and separator engineering for high-energy lithium-based batteries are comprehensively summarized. The contributions of biomaterials to stabilizing electrodes, capturing electrochemical intermediates, and protecting lithium metal anodes/enhancing battery safety are specifically emphasized. Furthermore, advantages and challenges of various strategies for fabricating battery materials via biomaterials are described. Finally, future perspectives and possible solutions for further development of biomaterials for high-energy lithium-based batteries are proposed.