MHP as a Strategic Alternative Feedstock for Battery Materials Until Recycling Infrastructure Matures

The global energy transition has led to a significant increase in demand for critical raw materials such as nickel and cobalt, driven by the rapid growth of electric vehicles and renewable energy storage systems. While the European Union and other regions are investing heavily in battery recycling infrastructure to meet sustainability goals, these facilities are still under development or in the early deployment stage. During this transitional period, Mixed Hydroxide Precipitate (MHP) is proving to be a technically viable and logistically reliable intermediate product, serving as a stable source of battery-grade nickel and cobalt. This article discusses the production methods, industrial compatibility, and strategic relevance of MHP in the battery value chain, highlighting its potential as a bridging solution until end-of-life battery recycling becomes fully operational.

The move towards decarbonised energy systems, electrification of transport, and expansion of renewable energy storage has put significant pressure on the supply of battery-grade raw materials. Nickel and cobalt play essential roles in high energy density cathode chemistries such as NCA (Nickel-Cobalt-Aluminum) and NCM (Nickel-Cobalt-Manganese). In response, the European Union has introduced a comprehensive regulatory framework, notably Regulation (EU) 2023/1542, to ensure the responsible sourcing and circular management of batteries, including targets for collection, recycling, and material recovery.

However, the physical infrastructure required to achieve these targets is still in its infancy. Most commercial recycling facilities in Europe are still in the pilot or early industrial phases, and the volume of end-of-life batteries is currently insufficient to support large-scale operations. Therefore, the implementation of bridging strategies is essential to ensure a secure and sustainable supply of feedstock until the recycling ecosystem matures. One such strategy is the use of Mixed Hydroxide Precipitate (MHP) as a transitional raw material.

MHP is typically produced from lateritic nickel ores via hydrometallurgical processing, most commonly High-Pressure Acid Leaching (HPAL) or atmospheric leaching, followed by precipitation using alkaline agents such as magnesium oxide or sodium hydroxide. The resulting solid product contains approximately 30–40% nickel and 1–4% cobalt, depending on the ore and process conditions. MHP is not a finished product, but an intermediate that can be further refined into battery-grade nickel sulfate (NiSO₄) and cobalt sulfate (CoSO₄) through standard refining techniques such as acid leaching, solvent extraction, ion exchange, and crystallisation. MHP's compatibility with existing refining infrastructure makes it a particularly attractive option for battery raw material supply chains.

Another key benefit of MHP is its high level of production flexibility. The manufacturing process utilises a variety of technologies and requires less capital investment when compared with integrated battery-grade sulfate production. Furthermore, in comparison with pyrometallurgical processing, MHP production typically results in reduced energy consumption and carbon emissions. According to the International Energy Agency (IEA, 2022), when powered by renewable energy sources, HPAL-based MHP plants can achieve up to 30-40% lower CO2 emissions than conventional ferronickel or matte production.

On a global scale, major MHP producers include countries such as Indonesia and the Philippines, with Chinese investments playing a key role in this development, aiming to secure cathode material supply. Europe, facing challenges in sourcing sufficient domestic feedstock, is presented with the opportunity to strategically incorporate MHP imports into its supply chain as a short- to medium-term solution. Concurrently, European refining facilities could undergo upgrades to enhance their efficiency in processing imported MHP, thereby strengthening strategic autonomy and reducing reliance on Chinese-controlled supply networks.

While battery recycling remains the long-term solution for achieving greater resource circularity, the timeline for its full implementation is several years. Until then, it will be essential to use hybrid sourcing strategies that combine both primary and secondary inputs. In this context, MHP can serve not only as a stopgap measure but as a structurally important feedstock, especially as end-of-life battery volumes remain low and collection networks are still developing.

In order to capitalise fully on the potential of MHP, a number of actions are recommended. Firstly, Life Cycle Assessments (LCA) should be conducted in order to quantify and validate its environmental performance. Secondly, exploring international supply agreements and partnerships is recommended in order to diversify sources and ensure stable imports. Thirdly, the EU industrial policy should consider supporting local refining capacity for MHP in order to reduce external dependencies.

In conclusion, MHP presents a technically robust and strategically sound alternative to battery recycling feedstocks during the infrastructure buildup phase. With appropriate safeguards, transparency, and sustainability practices, it can play a pivotal role in Europe's battery value chain. This would be both as a bridge to a circular economy and as part of a resilient long-term materials strategy.

References

1. International Energy Agency (IEA), The Role of Critical Minerals in Clean Energy Transitions, 2022.
2. European Commission, Regulation (EU) 2023/1542 on Batteries and Waste Batteries, 2023.
3. Wood Mackenzie, Global Nickel Market Outlook, 2023.
4. Roskill, Nickel for Batteries – Market Report, 2023.
5. Xu, M., et al., Hydrometallurgical Recovery of Critical Metals from Used Batteries, Journal of Sustainable Metallurgy, 2021.
6. Nickel Institute, MHP Production and Market Trends, Technical Bulletin, 2022.