One of the most popular types of batteries that power today’s ITC society, including smartphones and EVs, are lithium-ion batteries (LIBs). The Li-ion electrolyte moves the Li-ions back and forth between the positive and negative electrodes, charging and discharging the LIBs over and over again. Due to their voltage resistance and ionic conductivity, organic electrolytes like liquid ethylene carbonate (EC) and their gels have typically been used as the Li-ion electrolyte. However, because liquids and gels can catch fire, it is preferable to switch to more secure polymeric solid electrolyte.
As impact-resistant Li-ion electrolytes, polymeric solid electrolytes like polyethylene glycol (PEG) have been proposed. The Li-ion conductivity at room temperature, however, drops significantly to about 10-6 S/cm because PEG-based polymer electrolytes crystallize close to room temperature.
In order to address this issue, a research team created a novel kind of polymeric solid electrolyte by fusing a porous polymer membrane with numerous micron-sized pores with a photo-crosslinkable polymer electrolyte based on polyethylene glycol (PEG). A wide potential window (4.7 V), high Li-ion conductivity in the 10-4 S/cm class, which is equivalent to a liquid and sufficient for practical use, and a high Li-ion transference number were all achieved by the polymeric solid electrolyte (0.39). Natural diffusion causes the li-ions that are transferred in the electrolyte to move in different directions. One of the causes of the decline in ionic conductivity is that the distance between electrodes is several millimeters to ten millimeters and does not always move linearly. So, in this study, photocross-linked PEG-based solid polymer electrolytes were mixed with micron-sized porous membranes to make them work better.
Due to the incorporation of a porous membrane, this polymeric solid electrolyte not only exhibits high performance as an electrolyte but is also anticipated to be successful in preventing the formation of Li dendrites (dendritic crystals), which can result in ignition. By making LIBs that are safe and work well, this goal will help meet the seventh SDG, which is to have a sustainable energy supply.
