Potassium-ion battery vs lithium-ion battery

he world’s first 18650 cylindrical potassium-ion battery has recently been launched, offering a sustainable and cost-effective alternative to traditional lithium-ion batteries. This battery represents a new class of rechargeable batteries that use potassium ions as charge carriers, unlike the more common lithium-ion batteries.

The 18650 potassium-ion battery reportedly has a nominal voltage of 3.7V and an energy density of 160-180Wh/kg, comparable to lithium iron phosphate batteries. This article analyzes the differences between 18650 potassium-ion batteries and 18650 lithium-ion batteries.

Comparison of 18650 Lithium-Ion and Potassium-Ion Battery Technologies

Working Principles

Lithium-ion batteries use lithium ions as charge carriers, while potassium-ion batteries use potassium ions. Both adopt the same 18650 cylindrical size specification, making them easy to integrate into existing devices.

In terms of performance, potassium-ion batteries excel in cycle life and discharge performance, especially in electric vehicles, performing comparably to lithium-ion batteries. Both battery types achieve energy densities of 160-180Wh/kg, ensuring compatibility with modern electronic devices.

Key Material Differences

The main material difference lies in their charge transport ions: lithium vs potassium.

• Lithium-ion batteries often require critical minerals like nickel, cobalt, copper, and lithium.
• Potassium-ion batteries reduce dependency on these scarce minerals, making them more cost-effective.

Potassium-ion batteries operate at a standard voltage of 3.7V, ensuring compatibility with modern electronics and energy storage systems.

Charge and Discharge Mechanisms

Both battery types work by inserting and extracting ions from the electrodes to store and release energy:

• Lithium-ion: During charging, lithium ions move from the cathode to the anode through the electrolyte, forming lithium metal. During discharge, they return to the cathode.
• Potassium-ion: Potassium ions move similarly from cathode to anode during charging, forming potassium metal, and return during discharge.

Advantages of Potassium-Ion Batteries

1. Higher Overall Energy Density: Potassium ions have a higher electrode reaction potential, storing more charge at the same mass and achieving greater energy density.
2. Lower Cost: Potassium is abundant, reducing production costs and improving economic feasibility, especially for energy storage applications.

Disadvantages of Potassium-Ion Batteries

1. Shorter Lifespan: Potassium-ion batteries have lower cycle life due to changes in electrode materials like oxidation and shedding after repeated cycles.
2. Cycle Degradation: Performance declines over multiple charge/discharge cycles, resulting in reduced efficiency.

Performance Comparison with Lithium-Ion Batteries

Lithium-ion batteries excel in high energy density, fast-charging, and long lifespan. Key points:

• Ternary lithium batteries gained rapid market share after 2017 due to high energy density.
• Lithium iron phosphate batteries surpassed ternary lithium batteries in 2021.
• In 2022-2023, installation share of lithium iron phosphate batteries reached 62.4% and 67.6%, respectively.
• Liquid lithium batteries are nearing their energy density limit, while solid-state batteries may reach 500Wh/kg, representing the future of lithium battery technology.

Conclusion

Lithium-ion batteries remain the mainstream choice due to high energy density, fast charging, and long lifespan. Meanwhile, potassium-ion batteries are emerging as a promising alternative with cost advantages, comparable energy density, and the potential to replace traditional lead-acid batteries in specific applications.

As potassium-ion technology matures, it could become an important player in energy storage and sustainable battery solutions.

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