Fast-charging lithium-ion batteries require a systems engineering approach

Abstract

Fast charging has emerged as a key enabler for the widespread adoption of electric vehicles and portable electronics¹. However, achieving fast charging without compromising battery lifespan, safety, or energy density remains a complex challenge². At the core of this difficulty is the inherently multi-scale, multi-physics nature of battery behaviour, which spans materials³, electrochemical kinetics⁴, thermal management⁵, and mechanical stability. A battery is inherently an active, non-equilibrium device, meaning that heterogeneity is an inevitable and even necessary consequence of its normal operation. Yet, these same heterogeneities can cause significant problems if they become too severe, either causing reductions in performance, shortened cycle life, or resulting in dangerous failure modes. In dealing with these, adopting a holistic systems engineering approach becomes necessary for advancing battery design.

Battery research is often conducted through a reductionist lens, with individual disciplines focusing on isolated components — most notably through a materials-centric approach aimed at maximizing local performance. However, a narrowly scoped optimization frequently overlooks critical system-level interactions and constraints. As a result, solutions that perform exceptionally well in controlled environments may offer limited value at the cell, module, or pack level — especially under demanding conditions such as fast charging. While industry tends to adopt a more product-oriented approach, aiming to deliver integrated solutions that balance performance, cost, and safety, this integration also has limitations. Departmental silos exist even in industry, and the few integrated industrial tools and models remain proprietary and inaccessible to the broader research community because they are considered extremely valuable. We believe that both academia and industry can accelerate battery development by breaking down disciplinary boundaries, sharing more openly, and embracing a systems engineering approach that aims to balance the different heterogeneities that emerge during operation.