A Metal‐Free and Biotically Degradable Battery for Portable Single‐Use Applications

Abstract

waste electrical and electronic equipment (WEEE) generated after their disposal. The large quantities of WEEE and the wide variety of materials they often contain (ferrous metals, nonferrous metals, noblemetal, chemicals, glass, and plastics) have raised a serious alarm on their potential adverse health and environmental consequences when incorrectly disposed of. Moreover, this waste can be regarded as a resource of valuable materials (e.g., Au, Pt, Li) that if not recovered, has to be extracted again, resulting in natural resource depletion and environmental degradation. Recovering these metals and satisfying the demand for cheap secondhand equipment has become profitable business in emerging economies, which has turned Asia (in particular, China and India) and Africa into recipients of 90% of globally exported WEEE. [1] However, dismantling procedures are often carried out in inappropriate infrastructures with discarded components being openly incinerated and disposed of in unlined landfills that lack monitoring of leachate recovery systems of any kind. Due to their content of heavy metals, batteries are one of the most hazardous components of e-waste. For this reason, many Organization of Economic Cooperation and Development (OECD) countries have established regulations on the maximum permitted content of certain metals such as mercury or cadmium and the mandatory recycling of spent batteries. [2] Lithium-ion batteries are today the most predominant energy sources in portable applications because of their high energy density, low sensitivity to temperature variations, and no memory effect when recharging. [3] However, they are starting to raise important concerns related to the relatively low abundance of lithium metal-which is likely to increase the environmental impact of its extraction methods-and the large amount of CO 2 generated during battery manufacturing. In fact, its life cycle assessment determines that the use of lithium is only justified in rechargeable applications beyond hundreds of cycles, which clearly prohibits its use as primary batteries. [3,4] Despite all these worrying facts, battery recycling is far from meeting the goals set in developed regions (less than 30% of sold batteries are collected for proper recycling) and it is practically inexistent in low resource settings. [5] The most alarming issue is that consumption of batteries is expected to rise significantly in the following years due to the growth of small-sized portable appliances in the Information and Communications Technology This article presents a new approach for environmentally benign, low-cost batteries intended for single-use applications. The proposed battery is designed and fabricated using exclusively organic materials such as cellulose, carbon, and wax and features an integrated quinone-based redox chemistry to generate electricity within a compact form factor. This primary capillary flow battery is activated by the addition of a liquid sample and has shown continuous operation up to 100 min with an output voltage ...

Biopolymer Electrolyte Membranes (BioPEMs) for Sustainable Primary Redox Batteries

“…[28,38] Thus, a dedicated setup was designed and four electroactive species were selected for the crossover test.…”

“…[28] The BioPEMs here presented have been synthesized from natural abundant polymers like chitosan, cellulose, and starch in order to ensure their eco-friendliness and sustainability. [28] The BioPEMs here presented have been synthesized from natural abundant polymers like chitosan, cellulose, and starch in order to ensure their eco-friendliness and sustainability.…”

“…The objective of this work is to develop membranes based on biopolymers that represent an eco-friendly, sustainable, and naturally derived components of biodegradable portable power sources. [28] The BioPEMs here presented have been synthesized from natural abundant polymers like chitosan, cellulose, and starch in order to ensure their eco-friendliness and sustainability. Additives such as glycerol, ionic liquids, and urea have been used to fulfill the essential electrolyte membrane properties.…”

Evaluation of Redox Chemistries for Single-Use Biodegradable Capillary Flow Batteries

“…Further details about the device fabrication and structure can be found elsewhere. 41 The device is activated by adding 1 mL of DI-H 2 O and the OCP is monitored for 1 hour. During this measurement period, a cell polarization curve is measured and recorded every 5 minutes in potentiodynamic mode from OCP to zero volts.…”

“…[38][39][40] Recently, a new concept of single-use capillary flow batteries was introduced, which can be disposed of by the biotic degradative process. 41 This allows the battery to close its life cycle to nature at its end-of-life, which complies well with the circular economy and the concepts of green electronics as the associated waste is minimized from the device conception. The concept leverages advances in paperbased fuel cells which enable self-pumping and microfluidic fuel cells with flow-through porous electrodes which enable high power densities.…”