Magnesium Carbonate in New Energy Batteries: A Promising Future

Magnesium carbonate (MgCO₃) has evolved from a marginal additive to a core regulatory material for performance and safety in the new energy battery sector. Leveraging its abundant resources, low cost, and high controllability, it plays a pivotal role in optimizing lithium-ion batteries, constructing solid-state battery interfaces, and advancing magnesium battery R&D. With ongoing technical breakthroughs, it is set to become a vital force in driving batteries toward higher safety, lower costs, and longer lifespans. The following is a deep dive into its core applications, technical breakthroughs, market prospects, challenges, and trends.

I. Core Application Scenarios: Empowering Battery Performance Upgrades

Through various forms (nano-scale, porous, coated) and specialized processes, magnesium carbonate is achieving performance breakthroughs across lithium-ion, solid-state, and magnesium battery systems:

1. Lithium Battery Cathodes: Structural Stability and Cycle Enhancement

Coating and Doping: As a coating or dopant, MgCO₃ stabilizes the surface of cathode materials like Lithium Iron Phosphate ( LFP ) and high-nickel ternary ( NCM ) batteries. It prevents structural collapse during charge-discharge cycles. Modification with MgCO₃ can improve the capacity retention of LFP by 10%–15% after 500 cycles.
Crystal Regulation: Magnesium oxide ( MgO ) generated via thermal decomposition regulates the crystal structure, prevents abnormal grain growth at high temperatures, and improves ion diffusion rates.
Acid Neutralization: It neutralizes hydrofluoric acid ( HF ) in the electrolyte, reducing free HF to below 20 ppm. This limits metal dissolution, lowers interfacial impedance, and enhances high-temperature cycling stability.

2. Battery Separators: Strengthening Safety and Blocking Dendrites

Ceramic Coating: Using MgCO₃ as a precursor to create an MgO ceramic layer can reduce the thermal shrinkage of PE separators at 150°C from 60% to below 5%. It also improves puncture resistance by 40%, effectively preventing short circuits.
Micro-pore Formation: Ultrafine MgCO₃ creates uniform micro-pores in the separator, enhancing ion conduction efficiency while blocking lithium dendrite penetration, thereby reducing the risk of thermal runaway.

3. Electrolyte: Enhancing Safety and Controlling Side Reactions

Thermal Stability: Adding 0.5%–2% MgCO₃ can increase the initial decomposition temperature of the electrolyte by 15–20°C.
Gas Suppression: It reduces gas production by 30% after 48 hours of storage at 80°C, significantly lowering the probability of thermal runaway. It also protects the interface between the electrode and electrolyte by neutralizing acidic substances produced by hydrolysis.

4. Solid-State Batteries: Building Low-Impedance Interfaces

Interface Construction: Nano- MgO derived from MgCO₃ can be composited with sulfide or polymer electrolytes to build high-stability, low-impedance interfaces for both anodes and cathodes. These technologies are expected to enter the pilot phase by 2026.
Compatibility: It improves the compatibility between solid electrolytes and electrodes, boosting ion transport efficiency and accelerating the commercialization of solid-state batteries.

5. Magnesium Batteries: A Core Raw Material for a New Frontier

Anode Material: Carbonized MgCO₃ can serve as an anode material, enabling reversible magnesium intercalation/de-intercalation with a theoretical capacity as high as 2200mAh/cm³ , providing a low-cost, high-safety solution for the “post-lithium” era.
Cathode Precursor: It can be composited with transition metal oxides to synthesize magnesium-ion intercalation compounds, meeting the high specific capacity requirements of magnesium batteries.

II. Technical Breakthroughs: From Basic to Customized Applications

The rising value of MgCO₃ stems from continuous innovation in preparation and application:

Nano-sizing and Morphology Control: Techniques like microfluidics and spray drying are used to produce ultrafine MgCO₃ ( 20–200 nm ). Its high specific surface area increases loading capacity and reactivity.
Surface Modification and Composites: Modification with PEG or chitosan improves dispersibility and compatibility in electrodes and separators. Co-coating with Al2O3 or Li3PO4 forms a composite protective layer for enhanced stability.
Green Preparation: Utilizing magnesium sources from salt lake brines or industrial waste, combined with gradient crystallization and membrane separation, enables the large-scale production of 99.99% high-purity MgCO₃ with minimal environmental impact.

III. Market Prospects: Explosive Demand and Cost Advantages

Rapid Growth in Demand: In 2024, global magnesium carbonate consumption in the power battery sector reached 98,000 tons, a 62% year-on-year increase. Breakthroughs in magnesium-based batteries are expected to drive a 300% surge in related demand to 32,000 tons by 2025. By 2028, China’s demand for high-purity MgCO₃ in the battery sector is projected to exceed 180,000 tons.
Significant Cost Advantage: Battery-grade MgCO₃ costs only 1/20th that of cobalt sources. China’s abundant magnesium resources allow the industry to reduce reliance on rare metals like cobalt and nickel, lowering overall battery costs.
Policy-Driven Development: Government planning targets an 85% localization rate for high-purity MgCO₃ used in lithium battery separators by 2025, forcing industrial technical upgrades and releasing sustained demand.

IV. Challenges and Future Trends

1. Core Challenges

Scaling Bottlenecks: Nano-scale MgCO₃ tends to agglomerate during continuous ton-level production, leading to poor batch consistency. High costs for lab-grade products currently limit mass application.
Optimization Complexity: Different battery systems have varying requirements for particle size, morphology, and purity, increasing the difficulty of R&D and production.
Process Compatibility: Integration into existing battery production lines must be achieved without incurring excessive extra costs.

2. Future Trends

Customized Functional Development: Developing specialized MgCO₃ products (e.g., specific crystal types or high specific surface areas) tailored for high-nickel ternary or solid-state systems.
Multi-Technology Integration: Combining 3D printing and in-situ synthesis to achieve precise distribution of MgCO₃ within battery components.
Accelerated Magnesium Battery Commercialization: As technical hurdles are cleared, MgCO₃ will drive magnesium battery applications in energy storage and EVs, opening new growth spaces.

V. Conclusion

With its unique physicochemical properties and cost benefits, magnesium carbonate has made the leap from an auxiliary additive to a core functional material in the new energy battery sector. Its role in boosting performance, enhancing safety, and cutting costs makes it a vital pillar of the new energy industry. As technology matures and large-scale application advances, magnesium carbonate will facilitate the transition to high-safety, low-cost, and long-life battery systems, promising a bright future for the industry.