The function of lithium-ion batteries, like all other batteries, depends on smooth transport processes during discharging and charging between the anode and the cathode, i.e., the negatively and positively charged electrodes. Between the two electrodes there is a pure ion-conducting electrolyte. This guarantees the transport of the lithium ions between the electrodes but does not allow any electrons to pass. Put simply, the anode side releases lithium ions and electrons when the battery is discharged, i.e. when it is used. The electrons must now travel through the battery's external circuit to the cathode - current flows. To compensate, lithium ions also move through the electrolyte to the cathode, where they are stored. When charging, these processes are then reversed. The challenge for cell manufacturers now is to maintain these motion sequences even at ever higher battery energy densities, while the higher compression of the electrodes leaves less and less room for the ions to move. A task that only special carbon additives can perform.
Performance carbon additive for high performance batteries
The mass distribution of e-vehicles and their planned use as decentralized electricity storage systems is tied to one key product: the lithium-ion battery. Their properties in terms of the smallest possible size with the highest possible performance and service life are also decisive for continued positive development. In the development of ever better lithium-ion batteries, cell manufacturers have increasingly reached technical limits in the recent past. An innovative battery additive helps to push these limits in the direction of higher performance.
Our contribution: Porocarb – a new material category for cell designers
Cell manufacturers have long been working with various additives for the electrodes in order to optimize lithium-ion batteries. The specialists at Heraeus Battery Technology have spent several years developing a completely new additive to market maturity. The product called Porocarb is a porous, synthetic carbon performance additive in form of dry carbon powder. As a synthesized carbon performance additive, the product can be tailored to the need of the specific cell design.
“Our product ca can be tuned in terms of particle size, pore size, pore volume, total surface area, electric conductivity, and thermal conductivity,” explains Dr. Dominik Samuelis, Head of Strategy at Heraeus Battery Technology. “It is thus adding a new degree of freedom to the cell design as allows ion transportation throughout the carbon volume.”
Our synthetic performance carbon additive focuses on providing ionic and thermal conductivity in comparison to traditional additives that focus on electrical conductivity. Research results in pilot projects prove that Porocarb as a battery additive can improve discharge performance, which in case of e-mobility directly translates into a boost of driving range. Furthermore, the “high-power” Porocarb grades keep the cell heating to a minimum and allow longer discharge times while improving the cycle life of the battery.
In July 2021, Heraeus Battery Technology opened its first production plant for Porocarb in Rotterdam, which supplies cell producers and original equipment manufacturers. "We cover the entire critical steps of the manufacturing process ourselves," explains Dr. Dominik Samuelis.