Production and Characterization of Bacterial Cellulose Separators for Nickel-Zinc Batteries

Abstract

The need for energy-storing technologies with lower environmental impact than Li-ion batteries but similar power metrics has revived research in Zn-based battery chemistries. The application of bio-based materials as a replacement for current components can additionally contribute to an improved sustainability of Zn battery systems. For that reason, bacterial cellulose (BC) was investigated as separator material in Ni-Zn batteries. Following the biotechnological production of BC, the biopolymer was purified, and differently shaped separators were generated while surveying the alterations of its crystalline structure via X-ray diffraction measurements during the whole manufacturing process. A decrease in crystallinity and a partial change of the BC crystal allomorph type Iα to II was determined upon soaking in electrolyte. Electrolyte uptake was found to be accompanied by dimensional shrinkage and swelling, which was associated with partial decrystallization and hydration of the amorphous content. The separator selectivity for hydroxide and zincate ions was higher for BC-based separators compared to commercial glass-fiber (GF) or polyolefin separators as estimated from the obtained diffusion coefficients. Electrochemical cycling showed good C-rate capability of cells based on BC and GF separators, whereas cell aging was pronounced in both cases due to Zn migration and anode passivation. Lower electrolyte retention was concluded as major reason for faster capacity fading due to zincate supersaturation within the BC separator. However, combining a dense BC separator with low zincate permeability with a porous one as electrolyte reservoir reduced ZnO accumulation within the separator and improved cycling stability, hence showing potentials for separator adjustment.

Algae-Based Biopolymers for Batteries and Biofuel Applications in Comparison with Bacterial Biopolymers—A Review

“…Combining bacterial cellulose with Al 2 O 3 , Ulfa et al achieved a higher crystallinity than that of pure bacterial cellulose as well as increased porosity, electrolyte absorption, and conductivity, suggesting the use of this composite as a battery separator [ 159 ]. Heydorn et al investigated bacterial cellulose separators especially for nickel–zinc batteries and found high hydroxide and zincate ion diffusion as well as high electrolyte uptake for a porous separator and better zincate shielding for a denser separator, while combining both resulted in slower cell aging and less ZnO in the pores of the separator [ 160 ]. For Li-ion batteries, Chen et al suggested a bacterial cellulose/chitosan separator whose pore size could be tailored, as depicted in Figure 10 [ 161 ].…”

Effect of Sucrose Amounts on the Bacterial Cellulose Membrane's Breathability Properties

“…The growth of bacteria was limited when sucrose was used as a carbon source, probably due to the long pathway to convert sucrose into UDP-glucose. Some authors claimed that sucrose gave insignificant progress to cellulose production (Heydorn, Lammers, Gottschling, & Dohnt, 2023). However, the variation of sucrose amount differentiated the BC membrane growth, thickness and water-holding capacity properties (AL-Kalifawi et al, 2014;Jagannath, Kalaiselvan, Manjunatha, Raju, & Bawa, 2008).…”

“…Seddiqi et al (2021) and Keshk (2014) stated that the composition of culture media and the variation of carbon sources had affected the surface area, porosity properties and production yield of BC membranes. Previously said that utilisation of sucrose as a primary carbon source at certain concentrations can provide higher water holding and porosity value instead of glucose, fructose and glycerol, however lesser in yield and thickness of BC membrane (Heydorn, Lammers, Gottschling, & Dohnt, 2023;Al-Shamary & Al-Darwash, 2013). In addition, Ruka, Simon and Dean (2013) claimed that sucrose could produce a consistently high yield and thicker BC membrane, indirectly affecting pore size, porosity and water-holding properties.…”

Biofabrication with microbial cellulose: from bioadaptive designs to living materials

“…While BNC producers can catabolize many carbon sources, each species exhibits a sugar preference. For instance, glucose is preferentially utilized for K. xylinus, followed by lactose, 37 while Gluconacetobacter hansenii (G. hansenii) prefers sucrose and Komagataeibacter rhaeticus prefers mannitol. 38 More importantly, although enhanced BNC yield is undoubtedly most desirable for 3D biofabrication, other properties such as high mechanical integrity may also be advantageous.…”