A lithium-ion battery separator is one of the essential components of a lithium-ion battery structure. It has attracted wide attention as a result of providing efficient transmission channels of lithium ions, isolating pro and con electrodes to prevent short circuits. However, traditional petroleum-based separators encounter great challenges in battery recycling, charge transfer, sustainable use, etc. Cellulose provides an environmentally friendly, green alternative. In this mini review, we summarize the working principle of lithium-ion batteries and the main technical requirements for the use of separators as well as the latest research direction of cellulose-based lithium-ion battery separators. It brings breakthroughs in the fields of electrochemistry and energy chemistry, polymer chemistry, and energy materials and also provides a new inspiration

for the commercialization of lithium-ion-battery-coating separators.