Main content:
The solid electrolyte solves the problem of the solid electrolyte interface solid electrolyte interphase (SEI) film formed during the charging and discharging process of the liquid electrolyte and the lithium dendrite phenomenon, greatly improving the performance and service life of the lithium battery.
At present, solid state battery tech is constantly developing due to the active participation and policy support, but its widespread application still needs time.
What is solid state battery tech
Solid state batteries are regarded as the core direction of next-generation battery technology, which relies on replacing traditional liquid electrolytes with solid electrolytes to fundamentally solve the safety hazards of liquid batteries (such as thermal runaway and electrolyte leakage), while significantly improving energy density (theoretical value exceeding 500Wh/kg) and cycle life.
The development of solid state battery tech has improved the overall safety of batteries. And the energy density of the battery increases, for example, the energy density of all solid state batteries can reach 500Wh/kg, significantly improving the device's endurance. In addition, the solid state battery has a cycle life of over 1000 times, reducing usage costs and extending the lifespan of the equipment.
Classification and characteristics of solid state battery tech
Simply put, solid state battery tech can be divided into the following three types.
- Polymer electrolytes have good flexibility and processability, suitable for wearable devices and small smart devices.
- Oxide electrolytes have high ion conductivity and good stability, making them suitable for scenarios that require high charging speed and environmental adaptability.
- Sulfide electrolytes have high ionic conductivity and high energy density, but poor chemical stability, and interface compatibility issues need to be addressed.
The following text will introduce the technical characteristics and application status of three types of solid state electrolytes in solid state battery tech: polymers, oxides, and sulfides.
Performance leader- Sulfide electrolyte
If you are looking for the next generation of batteries with high energy density and long cycle life, sulfide electrolytes are undoubtedly the "king" players. Its ion conduction speed is very fast, and at room temperature, battery charging and discharging can achieve more efficient and responsive effects. For example, the sulfide electrolyte developed by Yili New Energy Technology has achieved a conductivity of 17mS/cm, and its 2Ah soft pack battery cell energy density can reach 410Wh/kg, with over 2000 cycles, showing impressive performance.
The industry of solid state battery tech is also rapidly advancing. CATL sulfide electrolyte has entered the trial production stage of 20Ah samples, with an astonishing energy density of 500Wh/kg; Gotion's all solid state experimental line has also been tested and started to be tested on the vehicle; Ruigu New Materials has taken the lead in achieving industrial mass production, with plans to put into operation a 100 ton production line by June 2025 and simultaneously build a second phase of a 1000 ton production line.
Of course, this solid state battery tech also faces challenges. For example, materials are prone to reacting with air and have relatively high costs. However, companies like Ruigu New Materials are striving to reduce costs and address stability issues by developing new water-soluble electrolyte materials and optimizing composite formulations.
Stability champion - Oxide electrolyte
Compared to "king" sulfides, oxide electrolytes are more like "stabilizing generals". For example, LLZO material is also very stable at high temperatures (up to 600 ℃), and is more easily compatible with high-voltage battery cathodes, such as high nickel ternary materials. By upgrading the solid state battery tech, such as adding tantalum element, the conductivity of LLZO (oxide electrolyte) has been significantly improved, while reducing the high-temperature sintering conditions required for manufacturing and enhancing material density.
In terms of industrialization, companies such as Ganfeng Lithium and Tailan New Energy have actively laid out and launched corresponding solid state battery products, some of which have even entered the mass production stage. This type of battery also performs quite reliably at extreme temperatures, such as maintaining 85% discharge capacity at -20 ℃, making it very suitable for large scale energy storage projects at the grid level.
Flexibility representative - Polymer electrolyte
If you are using a smartwatch, bluetooth headset, or drone, you may be using polymer electrolyte batteries. Its biggest advantage is good flexibility, easy processing, and suitability for small portable devices. For example, the CNC-PAN composite material developed by Qingdao University of Science and Technology not only has good conductivity, but also is very resistant to pulling and can be made into very thin and lightweight batteries.
However, its conductivity is still relatively low at room temperature, and it usually needs to be heated above 60 ℃ to achieve optimal performance, so there are limitations in high-power scenarios. But it has high security and is very suitable for the consumer electronics field that requires safety first.
It is worth mentioning that the new generation of lithium ceramic batteries (LCB) launched by Huineng Technology uses pure inorganic materials, completely eliminating organic solvents, with an energy density of 749Wh/L, and is expected to achieve mass production by 2025.
Application scenarios of solid state batteries
New energy vehicles: High energy density and safety make them an ideal power source for electric vehicles, significantly improving range and charging speed.
Consumer electronics: With smaller size, higher battery capacity, and better security, it meets the development needs of consumer electronics devices.
Energy storage field: It can be used for grid level energy storage, residential energy storage, and commercial energy storage to balance grid load and optimize energy costs.
Global solid state battery market size
According to EVTank data, the global solid state battery market size in 2023 is approximately $826 million, with a shipment volume of 1 GWh; It is expected that the market size will grow to 1.08 billion US dollars and the shipment volume will reach 3.3 GWh by 2024. The global shipment of solid state batteries has increased from 1GWh in 2023 to 3.3GWh in 2024, and is expected to reach 614.1GWh by 2030.
According to EVTank's forecast, the global solid state electrolyte market size will reach 36.62 billion yuan by 2030, with sulfide electrolyte shipments accounting for over 29.5%, and the market share in the all solid state battery sector exceeding 65%. It is expected that the global solid state battery market will exceed 250 billion yuan by 2030, with a compound annual growth rate (CAGR) of 18%.
The breakthrough of Solid State Battery Tech will not only reshape the competitive landscape in fields such as new energy vehicles, energy storage, and aerospace, but also drive the global energy transition into a new stage.
What is the problem with solid state batteries
But currently, the truly mass-produced all solid state batteries are still in the stage of tackling challenges, mainly facing three major challenges
Technological breakthroughs are still underway
At present, the core problem of all solid state batteries is "poor interface contact". Simply put, it means that the connection between the internal materials of the battery is not tight, which will affect the charging and discharging life. For example, some oxide type solid state batteries experience severe degradation after cycling up to 500 times in the laboratory. To address this issue, researchers are trying to use composite materials such as "sulfide+halide" combinations, or coating the surface of battery materials with "graphene" to enhance their stability.
The difficulty and cost of mass production are both high
Compared to traditional lithium batteries, the manufacturing requirements for all solid state batteries are higher. For example, sulfide materials must be manufactured under extremely high purity argon gas protection, and equipment investment is expensive; And the oxide process flow is also very complex. However, the good news is that companies like Ruigu New Materials have reduced production costs by 60% and energy consumption by half through the "solid-phase method".
Cost remains the 'threshold' for widespread consumption
At present, the cost of an all solid state battery is more than twice that of a traditional liquid state battery, reaching up to 5 yuan per watt hour. However, with the localization of raw materials and the expansion of production scale, it is expected that by 2028, the cost of sulfide batteries will decrease to about $120 per kilowatt hour, close to the level of liquid batteries, and the consumer market will also be more receptive.
Conclusion
With the breakthrough and large-scale promotion of solid state battery tech, all solid state batteries are expected to bring a real revolution to new energy vehicles, energy storage, and high-end electronic devices in the next 5 to 10 years. It will reconstruct the energy landscape and bring safer and more efficient product experiences to end users.
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