Nouryon has begun the first deliveries of AkuPure, a carboxymethyl cellulose (CMC) polymer targeted specifically at lithium-ion batteries, a market that is growing quickly due to increased demand for electric vehicles. CMC is a sustainable, bio-based water-soluble polymer used as a thickener, binder, stabilizer and film former.

AkuPure CMCs are specifically suited for aqueous binder systems in lithium-ion battery anodes which are used typically in combination with graphite and Styrene Butadiene Rubber (SBR) in anode coating to improve binding strength of active graphite on the copper collector. SBR alone cannot generate sufficient coating rheology and slurry stability for graphite powder.

Applying AkuPure CMCs will provide excellent dispersion of graphite particles and homogenous distribution of the binder. Secondary Lithium-ion batteries made using CMC show high capacity retention in general, but also at high C-rates.

AkuPure meets the ultra-high-purity requirement (greater than 99.5%) for use in lithium-ion batteries, where it improves the electrode coating process, increasing efficiency by helping the battery to retain and deliver power more effectively.

Customers in the battery market require ultrapure CMC, said Geert-Jan Beijering, Product Director at Nouryon. Impurities can interfere with performance or production efficiency; AkuPure has several properties key to the battery production process, including the speed at which it dissolves and its low level of insolubles.

The possibility to frequently charge and discharge a battery without losing performance under various temperature conditions is what matters most to our customers in this segment.

—Geert-Jan Beijering

The development further expands Nouryon’s end-market uses for CMC, a sustainable polymer derived from cellulose sources such as wood or cotton that is used as a thickener, binder and rheology modifier in markets ranging from mining to pharmaceuticals.

In January, Nouryon announced plans to acquire the CMC business of J.M. Huber Corporation. The business manufactures a complete line of CMC grades and serves customers in more than 80 countries, generating sales of around €135 million.