The separator is a porous membrane placed between negative and positive electrode, permeable to ionic flow while preventing electric contact of the opposite polarity electrodes. In the past decade, the separator membrane made from polymer, non-woven fabric mat, and inorganic composite. Usually separator membranes are made of conventional materials. Among environmental concerns, the biodegradable materials are used instead of the conventional materials, known as green separator membrane. Polylactic acid (PLA) is an alternative biodegradable polymer.However, there is several limitations of PLA including low chemical and thermal resistances; therefore, the cellulose is used to overcome these limitations. In this review, the cellulose modification is mainly discussed. Firstly, the cellulose was isolated from sugarcane bagasse. The successful isolation of cellulose was confirmed by FT-IR. Then, the PLA/cellulose membrane was fabricated via the phase inversion process to obtain the porous membrane suitable for using as a separator membrane in Li-ion battery.