55 E-Mobility Engineering | September/October 2025 Mining electrification | Insight that has been crumpled to pack its large surface area into a smaller volume, enabling more charges to be stored within a given volume. The cathode is a lithium metal oxide similar to that of a conventional battery. During charging, electrons move from the cathode to the anode via the external circuit, distributing themselves across the conductive graphene network of the anode, giving it negative potential. This attracts positively charged lithium ions (Li⁺) from the electrolyte. Approximately 90% of these Li⁺ ions electrostatically adsorb onto the graphene’s porous structure, creating electric double-layer capacitance, while the remaining ~10% intercalate into graphene defects, exhibiting batterylike behaviour. Meanwhile, the cathode’s loss of electrons creates positive potential, balanced by lithium extraction from the cathode material. Anions remain in the electrolyte. Discharging reverses the process. It is in the largest classes of surface mining vehicles where battery technology is still found wanting in terms of energy density, and the industry is hedging its bets that the SuperBattery could make a big difference. BEVs with payloads approaching 400 t and gross weights of more than 600 t need huge batteries that take hours to charge, but Skeleton and partner Siemens envisage SuperBattery-powered haul trucks operating for 45 minutes and recharging in just one minute. However, it is still uncertain which technology will come to dominate the heavies such as the ultra-class haul trucks, so the trend is toward ‘agnostic’ machines designed to accept either conventional diesel electric drivetrains or batteries (either of them with trolley assist) or fuel cell systems. Agnostic heavies and fuel cells For example, Komatsu is developing its Power Agnostic series. In July, it announced the start of field trials of a trolley-assisted, diesel electric example of its Power Agnostic (PA) 930E at Boliden’s Aitik copper mine in Gallivare, Sweden. The idea is that the modular PA platform enables customers to begin with diesel power and transition to battery or fuel cell power later, depending on their operational needs, technology readiness and pace of decarbonisation efforts. However, a 930E-4 converted to fuel cell power is already in operation. The nuGen hydrogen haul truck is a technology demonstrator based at the Mogalakwena Platinum Mine in South Africa. Mining giant Anglo American created the nuGen vehicle in cooperation with lead engineering and integration partner First Mode and equipment suppliers including Canada’s Ballard Power Systems, Williams Advanced Engineering (now Fortescue Zero), ABB and Komatsu. Its hybrid powerplant consists of an 800 kW proton exchange membrane fuel cell system from Ballard, and a 1.2 MWh lithium-ion buffer battery system from Williams, together capable of delivering 2.0 MW. A total of eight of Ballard’s FCmove-HD+ fuel cell modules are fed from the same number of highpressure tanks from NPROXX with total capacity of around 900 kg of H2. The hydrogen itself is electrolysed from water using a solar powered system from ENGIE. ABB provided the megawatt-scale DC-DC traction converters, trolleyassist components and grid-connection systems for hybrid operation. Komatsu provided the modified 930E truck chassis, and is now working with Anglo American to commercialise the nuGen vehicle in the 2026–2030 time frame. The fuel cell truck matches the 290 t payload and 500 km range of the original diesel version of the 930E. Refuelling takes 15 to 20 minutes. The company plans to convert more than 400 haul trucks by 2035. Also looking to the 2030s, solidstate batteries seem promising with specific energies of 300–500 Wh/kg, significantly reduced risk of thermal runaway and fire, and charge rates of 5C to 10C. However, their cost needs to fall from US $500 to $1000 per kilowatt-hour to below $200, and they must prove their durability. It is a similar story with sodiumion batteries in mining niches that can tolerate much lower specific energy and specific power outputs in exchange for lower costs and higher safety. The jury is still out on vehicle electrification options, meaning that we might well see more ‘agnostic’ power architectures going forward. An 800 kW PEM fuel cell system, based on eight Ballard FCmove HD+ modules is loaded onto the nuGen hydrogen haul truck. Together with a 1.2 MWh buffer battery, it delivers a total of 2.0 MW (Image courtesy of First Mode)
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