In the continuous evolution of battery technology, paper batteries, as an innovative battery technology, are gradually entering the public eye. To understand paper batteries, we must first understand how they work. Paper batteries operate mainly on the principle of electrochemistry, with plant cellulose as the key material, which not only provides structural support for the battery, but also plays an important role in the ion transport process. When the battery is in a working state, a redox reaction takes place inside the battery. Taking a zinc-manganese paper battery as an example, the zinc at the negative electrode loses electrons and undergoes an oxidation reaction to produce zinc ions, which flow to the positive electrode through an external circuit to form an electric current to power the external device. Inside the battery, the ions in the water-based electrolyte move directionally between the positive and negative electrodes under the action of the electric field to maintain the charge balance and ensure the continuous and stable operation of the battery.
Recently, Singaporean start-up Flint is developing paper batteries that are based on the above principles and use renewable energy chemistry. It has an electrical energy storage capacity of more than 220 watts per kilogram and an energy density comparable to existing lithium batteries. Made from purely sustainable materials such as plant cellulose, water-based electrolytes and recyclable metals, the batteries are fully sustainable and can be recycled and discarded in compost at the end of their life cycle.
From a design point of view, Flint rethinks the entire battery system, using cellulose as an ion transport medium and replacing non-renewable resources such as cobalt and lithium with metals such as zinc and manganese. Moreover, due to the versatility and flexibility of cellulose, manufacturers can design the battery structure according to the equipment space, rather than around a stationary battery brick. In terms of cost, Flint expects to eventually be able to manufacture batteries for about $50/kWh, less than half the average cost of lithium-ion batteries in 2024. In addition, this paper battery uses a water-based electrolyte, which is stable and non-toxic, virtually eliminating the possibility of a catastrophic fire, and is safer and more stable than lithium batteries.
Figure: The current situation of paper battery technology and China's breakthrough
In China, paper battery technology has also made remarkable breakthroughs in recent years. The scientific research team of the Institute of Flexible Electronics of Northwestern Polytechnical University has successfully developed a flexible paper-based metal battery. The team combined traditional papermaking technology with battery technology to create electrodes that not only have excellent electrochemical properties, but also retain the flexibility and thinness of the paper. The papermaking technology that can be industrially produced realizes the rapid batch preparation of electrodes, reduces the cost of battery production, and makes the production of flexible batteries more environmentally friendly and efficient.
The high flexibility and bendability of this flexible paper-based metal battery opens up new opportunities for the innovation of new electronic technology products. For example, combined with existing flexible display technologies, it is expected to promote the development of foldable phones and bendable devices, allowing folding screen phones to be folded at any angle. In the future, it is also possible to improve medical testing, promote the popularization of wearable electronic devices, and promote the sustainable development of battery technology.
China's breakthrough in paper battery technology echoes the international research and development exploration of paper batteries. Although the current paper battery technology may still be far from large-scale commercial application, whether it is the international research and development of sustainable paper batteries, or China's achievements in flexible paper-based metal batteries, it has opened up a new path for the future development of battery technology. With the continuous progress and improvement of technology, paper batteries are expected to play an important role in many fields such as new energy and electronic equipment, changing our life and industrial pattern.
