Callum McGuinn

Callum is an experienced UK & European patent attorney specialising in chemistry and materials science, with a specific interest and extensive experience in the fast-paced energy storage sector.  He represents clients through all stages of the patent life cycle, from drafting and prosecution to oppositions and appeals.

With a diverse and dynamic patent practice, Callum’s clients range from global chemical corporations to smaller UK-based businesses and individuals.

Callum's focused approach and proven track record in EPO oppositions have resulted in significant success.  He is adept at identifying those arguments which will be most likely to persuade the tribunal, and driving them home on the day, offering high-quality advocacy and positive outcomes for his clients.

His unique blend of technical knowledge and commercial acumen has been honed through an extended in-house secondment with a well-known British multinational chemicals company, primarily within their battery materials department. This experience provided him with invaluable insights into real-world problems and enabled him to foster strong relationships with inventors and really appreciate their perspective.

Callum's ability to quickly grasp complex technologies and delve into the intricacies of how things work sets him apart. A three-month secondment to a US law firm further enriched his understanding of cross-border patent practice, allowing him to provide comprehensive and strategic advice to clients operating on a global scale.

EPO Opposition Expertise

Callum has extensive experience representing clients on a range of chemical and materials related opposition cases. 

Notable cases include:

EP 2139906 T 2260/16: Nova Chemicals v Sasol. Successful defence of a patent relating to small-molecule catalysts for the preparation of alpha-olefins.

EP 2328905 T 2340/16: Nova Chemicals v Sasol. Successful defence of a patent relating to small-molecule catalysts for the preparation of alpha-olefins.

EP 1549699 T 0014/17: Unilever v P&G. Successful defence of a patent relating to water-soluble polymeric films for packaging fabric conditioners.

EP 3256317: Nova Chemicals v SABIC. Successful defence of a patent relating to recyclable stand-up pouches composed of polyethylene laminates.

EP 3279978: Johnson Matthey v ECOPRO. Successful revocation of a patent relating to lithium complex oxides used as cathode active materials in lithium-ion batteries. 

Qualifications and technical background

Callum has a Master’s degree in chemistry from Oxford University, which included a year of research focusing on spectroscopic and computational studies of small gas-phase transition metal clusters.

He specialises in energy storage solutions, particularly battery materials, predominantly lithium ion and other innovative battery technologies.  Other areas of expertise include:

• Polymers and polymer manufacture, particularly polyethylene
• Fuel cells
• Catalysts
• Inorganic materials, in particular glasses and alloys
• Small-molecule pharmaceuticals including antibiotics, antibody-drug conjugates and cancer therapeutics

Professional Career

Callum joined Mewburn Ellis LLP in 2012, qualifying as a Chartered Patent Attorney and European Patent Attorney in 2016. Callum became a Partner in 2021. He was awarded the Intellectual Property Litigation Certificate under the IPReg Rules and is authorised to represent clients at the UPC.

He has spent time on secondment to UK multinational chemical company and a top tier US law firm.

Callum now leads the firm’s battery technology focus team.

Recommendations and feedback

Callum is ranked in several of the leading IP legal directories such as:

Managing Intellectual Property (MIP) IP Stars

"Rising Star" and “Recommended lawyer” - 2018 - 2021

The Legal 500

"Key Lawyer" - 2022-2024

Client feedback:

"I have worked with Mewburn Ellis for almost 30 years, and with Callum for the last 5 years. Since then I have relied on Callum’s skills as a patent attorney to secure success during prosecution and opposition at the EPO. The quality and consistency of the work of Callum and the team at Mewburn Ellis has been essential to developing Nova’s strong IP portfolio in Europe and I have very much enjoyed working with them". Scott Chisholm - Nova Chemicals

Published Articles

Callum has written many articles on the topic of Energy Storage technologies, which mirrors his keen interest and expertise in the field.   His content has been featured in a variety of leading industry and IP publications such as: Batteries and Energy Storage Technology, Specialty Chemicals Magazine, Society of Chemical Industry, Energy Storage Journal, The Patent Lawyer, MIP, IAM, and IPM.

Utilising his interest in and knowledge of the battery field, Callum also led the production of Mewburn Ellis’ Battery Insights & IP Trends special report during 2022, culminating in its launch in early 2023.  The report generated strong interest from both the battery industry and a follow-up article in Patent Lawyer magazine.

Memberships and Affiliations

Callum is a member of the Chartered Institute of Patent Attorneys (CIPA) and The Institute of Professional Representatives before the European Patent Office (epi).

Callum has a close relationship with the publishers of the Intercalation Station newsletter and has provided content for this. 

Callum has also established links to the Faraday Institution where he has delivered IP training.  He is delivering an IP lecture as part of the syllabus for Battery Associates 2024 “Battery MBA”.