For a long time, issues related to battery life and cost have been technical bottlenecks restricting the development of electric vehicles. Through continuous technological innovation and improvement, battery technology has achieved rapid development, evolving from traditional lead-acid batteries to an advanced green power battery technology system including nickel-hydrogen power batteries, lithium cobalt oxide, lithium manganese oxide, polymers, ternary lithium, and lithium iron phosphate batteries. Significant progress has been made in terms of specific energy, specific power, safety, reliability, cycle life, and cost, with form energy playing an increasingly important role in these advancements.
Form energy, as a critical consideration in battery design, has influenced the evolution of these technologies by demanding optimal energy density in various form factors. Table 1-3 lists the main types of batteries currently used in electric vehicles and their basic characteristics. Among them, lead-acid batteries are widely used in electric vehicles, especially pure electric vehicles, due to their mature technology and low cost. Lithium-ion power batteries have advantages such as high capacity, high specific energy, long cycle life, and no memory effect, making them the main direction of research and development for power batteries in electric vehicles. In particular, the introduction of plug-in hybrid concepts has expanded the market space for lithium-ion power batteries, with form energy considerations driving innovations in both shape and performance.
Battery Performance Comparison
Table 1-3: Types and Basic Characteristics of Batteries for Electric Vehicles
| Battery Type | Specific Energy (W·h/kg) | Specific Power (W/kg) | Cycle Life (times) | Advantages | Disadvantages |
|---|---|---|---|---|---|
| Lead-acid battery | 50-70 | 200-300 | 400-600 | Mature technology, low cost, high reliability | Low specific energy, poor overcharge and over-discharge resistance |
| Nickel-cadmium battery | 40-60 | 150-300 | 600-1200 | Higher specific energy, long life, good overcharge and over-discharge resistance | Contains heavy metals, high price, poor memory effect |
| Nickel-hydrogen battery | 60-80 | 550-1350 | 1000+ | High specific energy, long life | High price, poor high-temperature charging performance |
| Sodium-sulfur battery | 150-200 | 200 | 800 | High specific energy, stable at high temperatures | Requires high operating temperature, poor cycle performance |
| Lithium-ion battery | 200-260 | 250-450 | 800-2000 | High specific energy, long life, favorable form energy characteristics | High price, certain safety issues |
International Power Battery Technology Developments
Currently, major international battery companies are investing heavily in the research and development of lithium-ion power batteries, achieving a series of significant technological breakthroughs. Form energy considerations are at the forefront of many of these innovations, as companies strive to maximize energy density while maintaining practical form factors for vehicle integration.
United States
Valence Technology's U-charge lithium iron phosphate battery, in addition to advantages such as high energy density and good safety, can discharge and store in a wide temperature range of -20~60℃. It is 56% lighter than lead-acid batteries, with operating time after one charge being twice that of lead-acid batteries, and cycle life 6-7 times that of lead-acid batteries.
Form energy innovations in American battery technology focus on both performance metrics and practical application scenarios, ensuring that high-energy solutions can be effectively integrated into various vehicle designs.
South Korea
SK Innovation's power lithium battery uses nickel-cobalt-manganese (NCM) ternary material for the positive electrode. The energy density of the battery cell reaches 180W·h/kg, and the energy density of the battery pack is 110W·h/kg. Korean researchers have also made significant progress in optimizing form energy, creating batteries that deliver high performance while fitting into increasingly compact vehicle designs.
International Battery Technology Roadmap
China's Power Battery Technology Status
In China, test results from authoritative departments indicate that the power density and energy density of domestically developed power batteries have reached internationally advanced levels for similar battery types, with significant improvements in battery safety performance. Form energy optimization has been a key focus in Chinese battery research, balancing energy density with practical application requirements.
The charge retention capacity of nickel-hydrogen power batteries has been significantly improved, with a charge retention rate of over 95% after 28 days of storage at room temperature. Significant progress and breakthroughs have been made in lithium-ion battery system integration technology and capabilities. The energy density of power battery systems using lithium iron phosphate materials reaches 90W·h/kg, while that of power battery systems using ternary materials (18650 cylindrical power batteries) reaches 110W·h/kg, with a cycle life exceeding the 5-year/100,000 km warranty requirement.
China's Battery Energy Density Achievements
National Battery Technology Development Plans
In terms of battery technology development planning, major developed countries worldwide have formulated national-level power battery research and development plans to strongly support the development of power battery technology and industry. These plans increasingly emphasize form energy as a critical parameter, recognizing that energy density must be balanced with practical form factors for successful commercialization.
United States
The U.S. Office of Energy Efficiency and Renewable Energy (EERE) released the "EV Everywhere Grand Challenge Blueprint," setting 2022 power battery system targets including 250W·h/kg mass energy density and $125/kW·h cost.
Long-term goals (through 2027) focus on post-lithium-ion technologies like lithium-air, magnesium-ion, and zinc-air batteries, with form energy optimization playing a key role in these next-generation developments.
Japan
Japan's New Energy and Industrial Technology Development Organization (NEDO) has developed detailed R&D roadmaps, focusing on lithium-ion battery cells, modules, standards, and evaluation technologies.
According to NEDO's roadmap, Japan's power batteries will use current lithium battery systems until 2025, then transition to all-solid-state batteries, with form energy considerations guiding material selection and design approaches.
Germany
The German government has formulated the National Electric Mobility Platform (NPE) plan, promoting production capacity building in power batteries through battery lighthouse R&D projects.
Germany aims to achieve 400W·h/kg energy density, 2000 cycles, and €75/kW·h cost by 2030, with form energy innovations integral to achieving these targets in practical applications.
South Korea
South Korea's Ministry of Knowledge Economy strongly supports R&D on lithium-ion batteries for electric vehicles, focusing on cells, modules, systems, and key raw materials.
The "World Premier Material" (WPM) project covers pure electric vehicles and energy storage, with form energy optimization helping balance energy density requirements for vehicles with cost considerations for storage applications.
China
China's Ministry of Science and Technology has supported R&D on high-power batteries for hybrids, high-energy lithium-ion batteries for pure electric drives, and next-generation new battery systems.
China's 2025 energy density target is 400W·h/kg using lithium-rich manganese-based cathodes and high-specific-energy silicon-carbon anodes, with form energy considerations guiding both material selection and system integration approaches.
Corporate R&D Progress
In terms of corporate R&D, various automakers and battery manufacturers have responded actively. In addition to vigorously developing lithium-ion batteries, leading companies are exploring new technologies where form energy plays a crucial role in commercial viability.
Contemporary Amperex Technology Co., Limited (CATL)
CATL is also actively exploring sodium-ion batteries. The working mechanism and structure of sodium-ion batteries are similar to lithium-ion batteries, with both achieving charge and discharge through the migration of metal ions between the positive and negative electrodes. The main difference lies in battery materials.
The cathode of sodium-ion batteries generally consists of sodium-ion layered oxides, while the anode uses hard carbon instead of graphite used in lithium batteries. Due to the more abundant reserves of sodium, sodium-ion batteries are not only cheaper themselves but also more cost-effective in their manufacturing process, with form energy characteristics that make them suitable for various applications.
On July 29, 2021, CATL released its first-generation sodium-ion battery with a cell energy density of 160W·h/kg, slightly lower than lithium iron phosphate batteries but with significant advantages in low-temperature performance and fast charging. It can reach 80% charge in 15 minutes at room temperature and maintain over 90% system discharge rate in -20℃ environment. CATL stated that the next generation of sodium-ion batteries will exceed 200W·h/kg in energy density, with basic industrial chain formation expected by 2023, further optimizing form energy for commercial applications.
CATL Sodium-ion Battery Advantages
- Abundant sodium resources, lower cost
- Excellent low-temperature performance
- Rapid charging capability (15min to 80%)
- Favorable form energy characteristics
- Next-gen target: 200W·h/kg
BYD
On March 29, 2020, BYD officially launched the Blade Battery. In a needle puncture test simulating a car accident, the Blade Battery ensures no smoke or open flame, with the battery surface temperature only around 30~60℃. Compared with traditional batteries that experience thermal runaway, it generates less heat and dissipates heat faster during short circuits, demonstrating excellent safety performance.
In addition to its "super safety" advantage, the Blade Battery also features super strength, super range, super low-temperature performance, super lifespan, super power, and the "6S" technical concept. The Blade Battery's innovative form energy approach allows for superior performance in a practical package.
Through a series of structural innovations, the Blade Battery achieves super strength while significantly improving the safety performance of the battery pack and increasing volume utilization by over 50%. Because the Blade Battery can greatly reduce the structural components that ternary lithium batteries need due to insufficient safety and strength, thereby reducing vehicle weight, although the cell energy density is not higher than that of ternary lithium batteries, it can achieve the same driving range as mainstream ternary lithium batteries. Additionally, the Blade Battery can achieve fast charging from 10% to 80% in 33 minutes, support the "Han" model's 3.9-second acceleration from 0 to 100km/h, withstand over 3,000 charge-discharge cycles with a cumulative driving distance of 1.2 million km, and demonstrate excellent low-temperature performance, establishing its comprehensive "superiority" over ternary lithium batteries, with its optimized form energy being a key factor in these achievements.
BYD Blade Battery "6S" Advantages
SVOLT Energy
In addition to BYD's Blade Battery, SVOLT Energy has also launched short blade batteries. SVOLT Energy's first-generation L600 short blade lithium iron phosphate cell has a capacity of 184Ah, adopting lamination technology, with significant improvements in energy density, cycle life, fast charging, and safety compared to current mainstream iron-lithium batteries.
On July 16, 2021, SVOLT Energy announced the mass production of the world's first cobalt-free battery with an energy density of 240W·h/kg, demonstrating impressive form energy optimization in a more sustainable battery design.
Other Innovators
NIO launched a 150kWh solid-state battery pack in January 2021, achieving an energy density of 360W·h/kg, scheduled for delivery in Q4 2022. Gotion High-Tech has developed solid-state battery products with energy density exceeding 360W·h/kg, gaining recognition and project appointments from automakers.
BAIC BluePark stated that it has completed the development of the second-generation solid-state battery cells, with battery system bench test verification and vehicle installation verification completed, showcasing the industry's collective progress in form energy optimization across various technological approaches.
Solid-State Battery Technology
Solid-state batteries, which use solid electrolytes instead of liquid electrolytes, are widely regarded as the future direction of lithium batteries due to their advantages over ternary lithium batteries in technical indicators and cost. Form energy considerations are particularly important for solid-state batteries, as their unique structure offers new possibilities for energy density and packaging efficiency.
Enhanced Safety
Solid electrolytes are non-flammable, non-corrosive, and non-volatile, offering superior safety performance compared to liquid batteries, with form energy characteristics that reduce thermal management requirements.
Higher Energy Density
Theoretically, solid-state batteries can achieve energy densities of 400~500W·h/kg, significantly improving the driving range of electric vehicles through superior form energy optimization.
Compact Design
Replacing liquid electrolytes and separators with solid electrolytes allows for thinner, smaller batteries, enabling miniaturization and薄膜化 of power batteries with optimized form energy.
In February 2021, Chery Automobile signed an agreement with Enovate Energy for a semi-solid-state power battery industrialization project with an energy density of 300~340W·h/kg. In March 2021, GAC Aion released the new-generation power battery safety technology "Magazine Battery," claiming that this technology has achieved for the first time that ternary lithium battery packs do not catch fire when punctured. These developments highlight the industry's progress in both solid-state technology and form energy optimization, pushing the boundaries of what's possible in battery performance and safety.
Solid-State Battery Development Timeline
The field of power battery technology continues to evolve rapidly, with form energy considerations playing an increasingly important role in driving innovations that balance performance, safety, and practical application requirements. From improvements in existing lithium-ion technologies to breakthroughs in solid-state batteries and alternative chemistries like sodium-ion, the industry is making significant strides toward more efficient, affordable, and sustainable energy storage solutions for electric vehicles and beyond.
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