E-Mobility Engineering | September/October 2023 31 materials for better removal of heat from the cells and down to the cooling plate. “As we develop our understanding of the cell and how it behaves with regard to potential thermal runaways, we might opt for thermal insulation or runaway retardant materials between cells as well. That’s an ongoing development but we’re sure it’ll come.” Embedded systems In addition to the systems discussed so far, Nyobolt’s applications team is also developing a range of embedded computing systems. These include the circuit boards for the BMS, cell monitoring cards and the controller, as defined by regulatory requirements on EV safety and Nyobolt’s own internal requirements for performance and mechanical integration. “In addition to defining the mechanical footprint in which each item of electronics has had to fit, we’ve also modelled and designed the boards to optimise for the amount of heat they might generate during operations and how we can remove that heat through the liquidcooling systems in the modules and onboard charger,” Ward says. “We’ve also gone through iterations of things like the PCBs’ integrations of connectors and their vibration performances to optimise our computing systems.” The high power density of Nyobolt’s batteries posed a slight risk of higher heat production by the electronics, given that the BMS has to work harder than COTS BMSs to monitor and control the much higher charging and discharging rates. This and the higher power throughput across the battery in general entailed selecting some connectors and board mount components optimised for higher current to minimise heat losses. “These types of components weren’t really available in the past, although we were able to use COTS products,” Dr Shivareddy says. “We just had to work hard to integrate them in a way that wouldn’t result in increased componentlevel internal resistances. “Part of the r&d for that included looking into applications with high-current electric and electronic subsystems, such as rail, marine or mining, which have PCBs designed for key points of cost efficiency and industrial utility. Going with an allnew design would have entailed more risk, as untested PCB designs naturally won’t have any data on how they can fail, even if they might have been more optimised and less over-engineered for our application.” Future plans Nyobolt aims to build 1 GWh of its batteries over the next 3 years, which equates to about 30,000 EV packs, although it notes that a lot of work lies ahead to secure its preferred supply chain partners, determine optimal manufacturing locations, and select the right customers – that is, OEMs who will understand how best to integrate and use its technologies. As mentioned, the Nyobolt EV will undergo further testing for gathering performance data to mature the battery, the OBC, the embedded systems and other key technologies. Nyobolt and CALLUM have stated publicly that the EV is a demonstration platform to its core, although Dr Shivareddy says the car’s scale of interested buyers makes the thought of becoming an EV manufacturer a tempting prospect. In terms of future battery development, he comments, “Battery evolution isn’t a linear phenomenon – history shows us that once a new battery works in an industry lab, it still takes at least 10 years for it to become commercially available. But we’re interested in trying to shorten that process, potentially with partners who understand what we want to achieve, from material extraction through to highvolume manufacturing methods. “We might be less focused on new chemistries or materials in the future, and more so on ways to combine mass-manufacturing solutions and filter new battery technologies through permutations of those. That could allow us to predict whether a new concept for battery technology will ever be compatible with manufacturing techniques, or if it just isn’t worth pursuing in r&d. There’s a finite amount of resources in the world, and all of it – minerals as well as money – should be allocated wisely.” Nyobolt’s future r&d might focus increasingly on ways to combine mass-manufacturing techniques and filtering new battery technologies through permutations of those (Courtesy of Nyobolt)
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