Nowadays lithium-ion batteries (LIBs) hold the leading position in the field of portable power sources. Despite their numerous advantages, LIBs also have several drawbacks, mainly high cost, low environmental friendliness, toxicity, flammability and difficulties with recycling of their components. One of the reasons these drawbacks exist is the presence of liquid organic electrolyte capable of ignition in commercial LIBs. Moreover, LIBs with liquid electrolyte have a number of limitations on the working potential values because of irreversible oxidation of the solvent and loss of the electrolyte. One of the solutions to these problems could be the use of polymer-based, specifically, gel-polymer electrolytes (GPEs) which are less prone to ignition, non-toxic and more stable in the high potentials area. Nevertheless, GPEs have lower functional properties in comparison with the liquid electrolytes, such as low ionic conductivity and thermal stability. In addition, electrode-electrolyte compatibility for LIBs with GPEs is lower than for liquid electrolytes.
Synthetic polymer poly(ethylene oxide) is widely used as a GPE because of its relatively high ionic conductivity. However, due to its low structure lability and, as a result, poor mechanical stability, it is prone to lithium dendrites growth, which short circuits the battery. An alternative may be a GPE based on natural polymers with a stable structure. In particular, cellulose has a highly crystalline structure. In addition, it is the most common natural macromolecule existing in many various forms. Another natural polymer – starch – has the same characteristics. Combination of good mechanical properties and possibility of structure modification to enhance the properties of the starting polymers allows for their use as a GPE for lithium-ion systems.
The aim of this project is design of new types of gel-polymer electrolytes based on natural polymers (cellulose and starch). The new GPEs will be used to create safe lithium-ion batteries with functional properties comparable to those of LIBs employing liquid electrolytes. By modification of the structure of the starting polymers in various ways (e.g., addition of other macromolecules, such as conducting polymers, to the pristine structure of the cellulose and starch), enhanced electrochemical properties will be achieved while saving their physical characteristics. The fundamental task of this research is to establish the relationship between the structure of the polymer electrolyte and the functional characteristics of the electrodes in a wide potential range.
The project This project is carried out jointly with the Iranian scientific group led by Dr Mehdi Salami-Kalajahi. In the course of the collaboration, the polymers synthesized and characterized by the Iranian group will be investigated as gel-polymer electrolytes in lithium-ion batteries by the group led by Dr Eliseeva S. N.
Dr Mehdi Salami-Kalajahi page| Title | Link |
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