Biomass is primarily known as a source of heat, fuels, and chemical building blocks. New research in Nature Communications. shows another application. Researchers describe how diverse biomass streams can be converted into hard carbon, a material that can be used in the negative electrode of batteries.
The study focuses on so-called hard carbon. This material is considered a key candidate for sodium-ion batteries. Specifically for this type of battery, there is a need for raw materials that are widely available and can be processed at reasonable costs. Biomass appears attractive for this purpose, but it also has a clear limitation. Residual streams from different chains vary significantly in composition. As a result, the quality of the end product also varies, making a reliable production route more difficult.
Fast heating, driven by data
The researchers are attempting to solve that problem with a combination of rapid heating and data-driven analysis. In the study, they used programmable Joule heating, in which materials are exposed to temperatures of 1000 to 2000 degrees Celsius for a short period. This approach was coupled with machine learning to analyze and compare a large number of synthesis routes.
According to the authors, this combination makes it possible to produce carbon materials with more predictable properties from very different types of biomass. The study describes an approach by which diverse biomass streams can be directed towards hard carbon with comparable performance.
High capacity and long life
The results reported by the researchers are robust. The material they refer to as hard carbon achieved a reversible capacity of 369 mAh per gram. They also report a high charging speed and stability of more than 5000 cycles at 3 A per gram.
In addition, the authors point out the speed of the process. The extra carbon step takes only tens of seconds and, according to the study, requires a limited energy input of 0,1 kWh per gram. That makes the method interesting on paper, although that does not automatically say anything about its feasibility on a large scale.
Still in an early stage
The publication focuses primarily on the question of how biomass can be converted into more predictable carbon materials for battery applications. As such, the study fits into the broader search for alternative electrode materials for sodium-ion batteries.
At the same time, this is still a laboratory study. The researchers show that their method works under controlled conditions, but for industrial application, questions regarding costs, scaling up, logistics, and consistent raw material quality also play a role.
For the time being, the study primarily shows that diverse biomass streams are being investigated not only as an energy source or chemical raw material, but also as a basis for battery materials.
Source: Nature Communications.
Researchers are working on new biomass-based battery materials, Photo for illustration, Magica, Pixabay
