Global lithium supplies are feeling pinched as demand for electric vehicles (EVs) increases, spurring researchers to seek out alternative materials to support battery manufacturing. Sodium-ion systems offer a promising replacement for lithium-ion chemistries, particularly when equipped with a new bio-based anode material advanced by researchers from Shandong Academy of Medical Sciences, China, and Kyushu Institute of Technology, Japan.

The researchers experimented with upcycling crab shell waste into hard carbon for use in sodium-based rechargeable batteries. After heating the shell material to temperatures exceeding 1,000° F, the carbon formed was added to a solution of either tin sulfide or iron sulfide as candidate transition metal dichalcogenides. When dried to form anodes, the porous, fibrous structure of the crab carbon provided a large surface area, which enhanced the material’s conductivity and ability to transport ions efficiently.

Tests conducted in a model battery demonstrated that both composites possessed good capacities and could last for at least 200 cycles. The development reported in ACS Omega could provide a route to upcycle other wastes and help develop more sustainable battery technologies.

Currently treated as a waste material, chitin is proving to be a sustainable component in diverse applications. For example, a technique is being promoted to extract the biopolymer from lobster shells for subsequent conversion into bioplastic material that can substitute for single-use plastics. Researchers are also using chitin waste from shrimp, lobster and crab shells to fortify cement.