Transient Rechargeable Battery with a High Lithium Transport Number Cellulosic Separator

Abstract

Transient batteries play a pivotal role in the development of fully autonomous transient devices, which are designed to degrade after a period of stable operation. Here, a new transient separator‐electrolyte pair is introduced for lithium ion batteries. Cellulose nanocrystals (CNCs) are selectively located onto the nanopores of polyvinyl alcohol membranes, providing mobile ions to interact with the liquid electrolyte. After lithiation of CNCs, membranes with electrolyte uptake of 510 wt%, ionic conductivities of 3.077 mS·cm–1, electrochemical stability of 5.5 V versus Li/Li+, and high Li+ transport numbers are achieved. Using an organic electrolyte, the separators enable stable Li metal deposition with no dendrite growth, delivering 94 mAh·g–1 in Li/LiFePO4 cells at 100 mA·g–1 after 200 cycles. To make the separator‐electrolyte pair transient and non‐toxic, the organic electrolyte is replaced by a biocompatible ionic liquid. As a proof of concept, a fully transient Li/V2O5 cell is assembled, delivering 55 mAh·g–1 after 200 cycles at 100 mA·g–1. Thanks to the reversible Li plating/stripping, dendrite growth suppression, capacity retention, and degradability, these materials hold a bright future in the uptake of circular economy concepts applied to the energy storage field.

Cellulose‐Based Electrolytes for Advanced Lithium‐Ion Batteries: Recent Advances and Future Perspectives

“…Cellulose-based electrolyte materials provide an opportunity for the development of high-performance transient LIBs. For instance, mittal et al reported a new transient separator-electrolyte pair for LIBs by combing cellulose nanocrystals and polyvinyl alcohol membrane, the gel electrolyte has an ionic conductivity of 3.077 mS cm À 1 , an electrochemical stability of 5.5 V. [21] The assembed LIB shows capacity of 94 mAh-g À 1 at 100 mA-g À 1 after 200 cycles. To make the gel electrolyte transient and non-toxic, the organic electrolyte was replaced by an ionic liquid (Figure 3).…”

“…For instance, mittal et al. reported a new transient separator‐electrolyte pair for LIBs by combing cellulose nanocrystals and polyvinyl alcohol membrane, the gel electrolyte has an ionic conductivity of 3.077 mS cm −1 , an electrochemical stability of 5.5 V [21] . The assembed LIB shows capacity of 94 mAh‐g −1 at 100 mA‐g −1 after 200 cycles.…”

The Role of Critical Raw Materials for Novel Strategies in Sustainable Secondary Batteries

“…These organic solvents can be hazardous and cannot be biotically degraded, so further attention is being focused to develop alternative electrolyte systems. Environmentally speaking, room temperature ILs, [ 156 ] or deep eutectic solvents (DES), [ 157 ] are more appropriate as they fulfill safety (wide electrochemical window, good thermal and chemical stability), efficiency, and environmental requisites. Another interesting alternative is aqueous electrolytes, which are widely used in zinc‐based batteries.…”

Transient, Biodegradable Energy Systems as a Promising Power Solution for Ecofriendly and Implantable Electronics

“…Figure 1 illustrates systems categorized with energy supplying methods, including 1) self-sustaining energy storage devices, for instance, battery and supercapacitor, that typically consist of one or merged electrochemical cells generating electrical power [24][25][26][27][28][29][30] ; 2) self-powering systems that collect electricity via converting other types of waste energy, such as physical/mechanical (triboelectric, piezoelectric) or chemical (galvanic) species [31][32][33][34][35] ; 3) energy transmission systems that can deliver power without wired connections, via radiofrequency (RF) electromagnetic fields and light illumination [36][37][38][39][40][41] ; and 4) envisioned energy sources for future directions, including thermoelectric, biochemical (biofuel, biopotential) sources, and ultrasonic waves. Each system operates with different mechanisms and timescales, requiring consideration of proper material selections, device structures, and integration strategies.…”