Li-ion batteries are used in everything from cell phones to electric vehicles (EVs), and the graphite material that makes up the anode can be 10 to 15 percent of the total cost of the battery. In addition, at present, about 70 percent of all graphite used in Li-ion batteries comes from China, so researchers around the world are working to find less expensive and less politically sensitive sources for the material.
A research team at Nanyang Technological University (NTU) in Singapore has developed a way to convert the waste paper that comes from single-use packaging, bags, and cardboard boxes, into a pure carbon material that can be used as the anode in Li-ion batteries. In testing, the carbon anode created by the NTU team proved to be at least twice as durable as the standard anode used in a cell phone battery and was capable of at least 1,200 charge and discharge cycles. The team also found that the anode created from waste paper was more resistant (up to five times more) to shock loads and rough handling than current anode materials.
The NTU process starts with paper waste, such as craft paper bags, which comprised nearly one-fifth of Singapore’s generated waste in 2020. Using a laser, thin sheets of paper are cut and joined together into different lattice geometries. These paper structures are then heated to 1,200 degrees Celsius in a furnace without oxygen, converting the paper into pure carbon, which is then used to make battery anodes.