Cohort 15 (2025): The EU Battery Passport, Sodium-Ion and Silicon Anodes

Cohort 15 arrived in December 2025 with a wide reading of battery industry trends, and the sessions kept returning to a single tension: the gap between where the technology is heading and where regulation, financing and physical infrastructure actually sit today. Across ten lectures, a run of participant office hours and a set of case studies, our cohort explored what it takes to move a cell from a promising data sheet to a bankable, compliant, safely deployed asset. The result was less a survey of hype and more a working map of the decisions professionals face this year.

Regulation moves from paper to practice

The cohort opened on a theme that shaped much of what followed: carbon footprint accounting and the EU Battery Passport. What used to be a distant policy conversation is now a compliance workstream with deadlines, and the sessions treated it that way. We looked at how a product carbon footprint is calculated, where the data has to come from along the value chain, and why traceability is becoming a commercial requirement rather than a reporting nicety.

That regulatory thread ran into an unexpected neighbour: fire. One lecture went beyond the burn marks into prevention, forensics and legal strategy for battery fires, and it reframed safety as something that sits between engineering and liability. When a pack fails, the questions are technical and legal at once, and the cohort examined how forensic investigation and documentation feed directly into risk and insurance conversations. Read alongside the passport work, the message was consistent: the industry is being asked to prove things it once simply asserted.

Chemistry and manufacturing under real scrutiny

On the technology side, our cohort explored the chemistries competing for the next decade. Silicon's role beyond graphite came up repeatedly, both in a dedicated lecture and in participant talks on silicon anode trends, with a clear-eyed look at energy density gains against swelling and cycle life trade-offs. Sodium-ion got similar treatment, but with a sharper edge. A lecture on cell design and degradation of commercial sodium-ion cells sat next to an office hour that openly questioned the technology's viability and picked apart common misconceptions. That pairing was deliberate. The cohort wanted the case for sodium-ion and the case against it in the same room.

Manufacturing grounded all of this. Sessions on the latest trends in battery manufacturing and on establishing a facility from engineering through to operational start-up made the point that chemistry choices are only as good as the line that can produce them at yield. Cell testing for integration and future-ready EV battery testing added the quality dimension, and a talk on using AI in battery information management hinted at where process control is heading. Solid electrolyte processing and long-life cell work rounded out a technology block that stayed practical throughout. A participant session on business and technical trends across battery packs, BMS and IoT extended the point into the systems layer, showing that a cell rarely fails or succeeds on its own. It lives inside a pack, a management system and increasingly a connected data environment, and the cohort explored how each of those layers adds cost, complexity and points of control. Electromobility and sound comfort control appeared as a reminder that end applications impose their own quiet constraints on how a battery is designed and packaged.

BESS economics and the geography of deployment

If one subject dominated the office hours and case studies, it was stationary storage. Battery energy storage systems appeared from almost every angle: fundamentals and real-world applications, utility-scale development lessons, hazard mitigation analysis from an independent power producer's seat, and the colocation of BESS with solar PV. The economics drew the most attention. A case study on revenue stacking for standalone BESS compared the UK, USA, Germany and Australia, and a talk on distributed BESS transactions in ERCOT showed how market design shapes what a project can actually earn.

The geography was striking. The cohort explored grid-scale BESS in the Middle East, storage's role across Latin America, India's energy storage opportunity, business cases for Vietnam, Eastern European countries entering the market, and the feasibility of Africa's battery value chain. Scaling utility-scale BESS in the US came up through a company case, as did microgrid applications. Taken together, these sessions treated BESS not as one market but as dozens of local ones, each with its own tariff structure, permitting reality and cost of capital.

Strategy, portfolios and the circular question

The cohort also stepped back to look at the industry as a business. Sessions on strategic battery recycling in Europe framed circular value creation as a roadmap rather than a slogan, connecting recovered materials back to supply security. Portfolio concentration and optimisation, battery lifecycle management from a customer-service view, and lifecycle thinking in aftermarket high-voltage servicing all pushed the same idea: value does not end when a cell ships. One case study assessing the acquisition of the Northvolt gigafactory assets in Sweden brought this into sharp relief, asking what distressed manufacturing capacity is actually worth and to whom. It was a fitting anchor for a cohort that spent much of its time weighing ambition against execution.

Key Takeaways

• The EU Battery Passport and product carbon footprint accounting have become live compliance work, not future policy, and traceability is now a commercial requirement.
• Sodium-ion was examined from both sides: commercial cell degradation data alongside a frank challenge to its near-term viability and the misconceptions around it.
• Silicon beyond graphite remains a density-versus-durability trade-off, discussed in both lecture and participant sessions on silicon anode trends.
• BESS economics were the cohort's centre of gravity, with revenue stacking compared across the UK, USA, Germany and Australia and market design lessons drawn from ERCOT.
• Storage was treated as many local markets: the Middle East, Latin America, India, Vietnam, Eastern Europe and Africa each carried distinct feasibility questions.
• Battery fire prevention, forensics and legal strategy reframed safety as an engineering and liability problem at once.
• Recycling in Europe and the Northvolt asset case tied circular value and distressed capacity into a single strategic question about what the industry is really building.