Comparison between potassium-ion batteries and lithium-ion batteries

Potassium-ion batteries and lithium-ion batteries differ in many aspects. The following is a detailed comparison:
Working principle
Both are essentially charged and discharged by ions being inserted and removed back and forth between the positive and negative electrodes. However, lithium-ion batteries use lithium ions as charge carriers, while potassium-ion batteries use potassium ions as charge carriers, which forms a subtle difference between the two in the working process.
Material cost
- Raw material reserves: Lithium resources are relatively scarce and unevenly distributed, mainly concentrated in a few countries and regions. Potassium resources are abundant in the earth's crust and have low acquisition costs, which makes potassium-ion batteries more advantageous in raw material supply, and there is a large room for cost reduction in the long run.
- Supply chain: The new potassium-ion battery uses common commercial components, including graphite anodes, diaphragms and electrolyte formulas, which simplifies the supply chain, enhances domestic manufacturing capabilities, and reduces dependence on essential minerals such as nickel, cobalt, copper and lithium; while lithium-ion batteries are highly dependent on specific minerals such as lithium in production, and the stability of the supply chain is easily affected by resource distribution and market fluctuations.
Performance characteristics
- Energy density: Lithium-ion battery technology is relatively mature, and the energy density is generally high. The energy density of common lithium-ion batteries can reach 200-300Wh/kg or even higher. Potassium-ion batteries currently have a relatively low energy density. For example, the world's first 18650 cylindrical shell potassium-ion battery has an energy density of 160-180Wh/kg, which is comparable to lithium iron phosphate batteries, but there is still a certain gap compared with lithium-ion batteries overall.
- Charge and discharge performance: The radius of potassium ions is larger than that of lithium ions. During the charge and discharge process, the insertion and deintercalation speed of potassium ions in electrode materials is relatively slow, which may cause the charge and discharge rate performance of potassium ion batteries to be inferior to that of lithium ion batteries. However, with the deepening of research, the charge and discharge performance of potassium ion batteries has been continuously improved through the development of suitable electrode materials.
- Cycle life: Lithium-ion batteries perform well in terms of cycle life. Some high-quality lithium-ion batteries can achieve thousands of charge and discharge cycles. At present, the structural stability of the electrode materials of potassium ion batteries is poor during the cycle process, resulting in a relatively short cycle life, but researchers are working hard to improve the electrode materials and battery design to improve its cycle stability.
Safety
- Thermal stability: Lithium ion batteries are prone to thermal runaway under abnormal conditions such as high temperature or overcharge or overdischarge, causing combustion or even explosion. Potassium ion batteries have relatively good thermal stability and a relatively low risk of thermal runaway, but research in this area is still in-depth.
- Electrolyte safety: The electrolytes used in both have certain safety hazards, but potassium ion batteries have a certain space in the selection and optimization of electrolyte systems, and it is expected to develop safer electrolyte formulas.
Application scenarios
- Lithium ion batteries: Due to their advantages such as high energy density and long cycle life, they are widely used in fields with high energy density requirements, such as portable electronic devices such as smartphones, laptops, and tablets, as well as electric vehicles, drones, and other vehicles that require high endurance.
- Potassium-ion batteries: Although their energy density and other performance indicators are not as good as those of lithium-ion batteries, they have certain application potential in areas that are not particularly demanding on energy density but are more sensitive to cost and resource sustainability, such as large-scale energy storage systems and low-speed electric vehicles, due to their advantages such as low cost and abundant resources.