Biomimetic Wood‐Inspired Batteries: Fabrication, Electrochemical Performance, and Sustainability within a Circular Perspective

Abstract

Nature's hierarchical materials offer exceptional multifunctional properties thanks to their evolution over millions of years to reach the most optimized organization in terms of function, structure, or chemistry. Exploiting the unique features of natural materials through biomimicry offers an exciting research field with large potential for new discoveries. Wood, as one of the most fascinating biomaterials, combines unique mechanical properties, an anisotropic hierarchical porosity optimized to provide rapid, and low tortuosity pathways for nutrient/water transport, abundance, and biodegradability. Accordingly, wood has inspired scientists to mimic its outstanding properties in artificial analogues to develop batteries with remarkable electrochemical performance. For instance, its sophisticated structure can be transferred to solid‐state materials through biomimetic templating to increase the lifespan and energy density of batteries, while its inherent hierarchical multi‐channeled structure allows the synthesis of current collectors with enhanced ion and electron diffusivity. This Review highlights the recent progress into the application of wood as a hierarchically porous and renewable material to develop different battery components, including the cathode, the anode, the separator, and current collectors. The potential of wood‐inspired batteries to lessen the pressure over critical raw materials and additional environmental sustainability benefits are highlighted within a circular economy perspective.

Self‐Promoting Energy Storage in Balsa Wood‐Converted Porous Carbon Coupled with Carbon Nanotubes

“…The light weight (150 kg m −3 ) and fast growth (12 ft. after germination within 6 months) make balsa wood stand out of all other woods in fabrication of highly porous carbon framework. [43][44][45] When balsa wood is sliced along the longitudinal direction of growth, a uniform porous structure without crossing annual growth rings will be obtained. Figure 1a illustrates the design concept and preparation of a carbon sheet/CNTs electrode.…”

Inspired by Wood: Thick Electrodes for Supercapacitors

“…For one, the carbonization process, a critical synthetic step for converting wood into carbon that involves raising and maintaining temperatures over 900 °C, consumes a large amount of inert carrier gases (usually N 2 , but sometimes more costly Ar is used) and considerable levels of specific energy (at least over 1 kWh/kg hydrocharbon ). 167 Besides, the low efficiency (∼9%) of the carbonization process, wherein 1 kg of hard carbon is obtained from 11 kg organic material (sugars), and the long residence time are both problematic for upscaling. As an alternative to conventional carbonization, microwave or flash-assisted carbonization methods have been suggested on the basis of their short processing time, which is around 30 min for microwave-based methods and a few seconds to minutes for flash-based methods, greatly reducing the energy requirement and increasing the overall efficiency.…”

“…In spite of the fact that natural wood is quite inexpensive, endowing raw wood and/or carbonized wood with suitable properties for effective electrode performance would inevitably accommodate cost- and energy-intensive processes. For one, the carbonization process, a critical synthetic step for converting wood into carbon that involves raising and maintaining temperatures over 900 °C, consumes a large amount of inert carrier gases (usually N 2 , but sometimes more costly Ar is used) and considerable levels of specific energy (at least over 1 kWh/kg hydrocharbon ) . Besides, the low efficiency (∼9%) of the carbonization process, wherein 1 kg of hard carbon is obtained from 11 kg organic material (sugars), and the long residence time are both problematic for upscaling.…”

Cellulose-Based Ionic Conductor: An Emerging Material toward Sustainable Devices

“…Conventional ICs based on petroleum resources require intensive processing and refining for resources extraction, which jeopardizes the environmental sustainability of the materials in terms of greenhouse gas (GHG) emission, contamination from oil spills, or the need for hazardous processes involving corrosive/toxic/ignitable materials. Shifting toward alternative materials such as cellulose, a nontoxic, renewable, and local resource (decoupling production from imports and solving supply chain bottleneck issues), 418 can solve the environmental concerns. Cellulose extraction is the first step influencing the environmental sustainability of cellulose-based ICs.…”