Bat­tery made with crab shells offers high per­form­ance and sustainability

Using a bio­de­grad­able elec­tro­lyte made from the same sub­stance as in crab, shrimp and lob­ster shells, research­ers at the Uni­ver­sity of Mary­land and the Uni­ver­sity of Hou­s­ton have developed a sus­tain­able zinc bat­tery. Rechargeable bat­ter­ies as green energy sources are import­ant allies for redu­cing reli­ance on fossil fuels and the emis­sion of green­house gases. The use of chitin, a bio­ma­ter­i­al, is a sus­tain­able approach for green and effi­cient energy-stor­age systems.

The grow­ing glob­al demand for renew­able energy and elec­tric vehicles has brought great­er need for bat­ter­ies that can store gen­er­ated energy and power engines. Non­ethe­less, such bat­ter­ies are not always sus­tain­able and can cause envir­on­ment­al and dis­pos­al prob­lems, with some com­pon­ents tak­ing cen­tur­ies to degrade.

As repor­ted in the journ­al Mat­ter, this new bat­tery is able to store power from large-scale wind and sol­ar farms, using a gel elec­tro­lyte made from chitosan, a deriv­at­ive product of chitin, which can eas­ily be obtained from sea­food waste.

Approx­im­ately two-thirds of the bat­tery can be degraded by microbes, com­pletely dis­solv­ing in soil in less than five months without any treat­ment, leav­ing just the met­al com­pon­ent, here zinc, which can be recycled. Addi­tion­ally, zinc is much more abund­ant on Earth than lithium.

The team examined the per­form­ance of the zinc – met­al bat­tery with this elec­tro­lyte, show­ing that the cells could oper­ate for 400 hours with an energy effi­ciency of 99.7% after 1,000 cycles, offer­ing the poten­tial for stor­ing energy gen­er­ated by wind and sol­ar for trans­fer to power grids. As well as being bio­de­grad­able, the new elec­tro­lyte is non-flam­mable, an import­ant safety factor.

Lead author Liang­bing Hu said, ​“we demon­strate the solu­tion can be found to achieve the high per­form­ance and bio­de­grad­ab­il­ity of mater­i­al at the same time… We hope this work can attract the research community’s atten­tion on the bio­de­grad­ab­il­ity of mater­i­als when devel­op­ing new mater­i­als for batteries”.

“We demon­strate the solu­tion can be found to achieve the high per­form­ance and bio­de­grad­ab­il­ity of mater­i­al at the same time… We hope this work can attract the research community’s atten­tion on the bio­de­grad­ab­il­ity of mater­i­als when devel­op­ing new mater­i­als for bat­ter­ies” said Hu.