On the other hand, recent work by Miettunen et al.demonstrated the use of cellulose nanofibril (CNF) aerogels asa quasi-solid electrolyte.30 CNF suspensions were fed into afluidizer, and the slurry was screen-printed onto the DSSCcounter electrode. The gel was instantly frozen by using liquidnitrogen and lyophilized, forming a CNF aerogel with >98%porosity. The liquid electrolyte (I−/I3− in 3-MPN) was drop-cast onto the aerogel, and the cell was subsequently assembled.The main advantage of using an aerogel in the DSSCfabrication protocol was the elimination of electrolyte-fillingholes in the counter electrode, which improved cellencapsulation by eliminating a common pathway of electrolyteleakage. Another significant advantage was that the aerogel wasuniformly wetted with the electrolyte, enabling an evendistribution of performance-enhancing additives, such as 4-tert-butylpyridine (4-tBP) and 1-methylbenzimidazole(NMBI). Conventionally, the electrolyte is injected into theelectrolyte-filling holes and laterally pushed through the solarcell. Because the nanoporous photoelectrode can filterelectrolyte components, the distribution of electrolyte additivesadsorbed on the photoelectrode is therefore nonuniform,315636Articlecausing varying performance at different ends of the device. The loss of overall performance due to this effect is particularly significant in large-scale devices, where the lateral path of electrolyte movement is much longer.