A dense instead of porous gel polymer electrolyte for lithium ion batteries is reported for the first time Its host is a renewable and environment friendly polymer, hydroxyethyl cellulose (NEC), The preparation of NEC membrane is very simple. The membrane is stable up to 280 degrees C, much higher than the melting points of those commercial separators based on polyolefin. The evaporation temperature of the organic electrolyte in the prepared gel polymer electrolytes is up to 75 degrees C. In addition, the gel polymer electrolyte shows good electrochemical performance including high ionic conductivity at room temperature, and a high lithium ion transference number. When tested as separator and electrolyte, a LiFePO4 positive electrode displays satisfactory electrochemical properties including high discharge capacity and stable cycling. These results indicate a very promising direction for a low cost and renewable gel polymer electrolyte for lithium ion batteries. (C) 2014 Elsevier B.V. All rights reserved.