What is the difference between polymer lithium batteries and lithium batteries?
The essential difference between polymer lithium batteries and traditional lithium batteries lies in the electrolyte form. Ordinary lithium batteries use liquid electrolytes and rely on separators to isolate the positive and negative electrodes; However, the polymer lithium battery uses solid/gel state polymer electrolyte, which has both ion conduction and physical isolation functions, and its structure is simpler. This feature enables its energy density to exceed 300Wh/kg (about 250Wh/kg for ordinary lithium batteries), and supports ultra-thin flexible packaging. This article will deeply analyze the differences between polymer lithium batteries and lithium batteries from the perspectives of technical principles, performance differences, application scenarios, and future trends? And reveal how polymer lithium batteries have become a potential stock in the era of new energy.
What is the difference between polymer lithium batteries and lithium batteries?
1、 The difference between polymer lithium batteries and lithium battery technology principles
1）. Core composition and bottleneck of lithium batteries
Traditional lithium batteries use liquid organic solvents (such as vinyl carbonate) as electrolytes, and the positive and negative electrodes are composed of materials such as graphite and lithium cobalt oxide. Although its energy density is as high as 150-250Wh/kg, the volatility and flammability of liquid electrolytes pose significant risks of thermal runaway. For example, in overcharge, short circuit, or high temperature environments, liquid electrolytes are prone to decomposition and gas production, causing battery bulges and even fires and explosions. In addition, the liquid system limits the flexibility of battery morphology and is difficult to meet the needs of flexible electronic devices.
2）. Innovative design of polymer lithium batteries
By replacing the liquid electrolyte with a solid polymer (such as polyethylene oxide (PEO)), and using gelled electrolyte and composite cathode materials (such as lithium iron phosphate), polymer lithium batteries have achieved dual upgrading of structure and performance. Solid electrolytes not only eliminate the risk of leakage, but their three-dimensional conductive network also enhances ion migration efficiency. Taking a certain brand of mobile phone battery as an example, the thickness of the battery cells using polymer system can be compressed to below 2mm, while traditional lithium batteries generally have a thickness exceeding 4mm due to limitations in electrolyte fluidity.
2、 Performance comparison between polymer lithium batteries and lithium batteries
1）. Energy density and cycle life
The theoretical upper limit of energy density for traditional lithium batteries is about 300Wh/kg, while polymer lithium batteries can increase their energy density to over 350Wh/kg due to the high ion conductivity of nanoscale solid electrolytes. For example, a solid-state battery model from a new energy vehicle company has a range of over 1000 kilometers, and its core relies on the optimization of polymer based cathode materials. In addition, the cycle life of polymer lithium batteries generally reaches over 2000 times, which is about 30% longer than that of liquid batteries.
2）. Safety: The essential difference in the risk of thermal runaway
In needle puncture experiments, traditional lithium batteries often experience severe smoke and fire due to electrolyte combustion, while polymer lithium batteries only briefly expand and self extinguish due to the non flammability of solid electrolytes. This feature enables it to pass strict safety certifications such as UL 1642 and IEC 62133, making it a suitable choice for high-risk scenarios such as electric aviation and energy storage power stations. The polymer electrolyte is non flammable, and there is no risk of thermal runaway during needle puncture experiments (liquid electrolyte detonates within 3 seconds). But the current manufacturing cost is 20% higher, mainly due to the complex solid-state electrolyte film formation process.
3）. Temperature adaptability
Polymer lithium batteries can maintain over 80% capacity in environments ranging from -20 ℃ to 60 ℃, while liquid batteries experience a significant increase in electrolyte viscosity at low temperatures, leading to a sharp drop in discharge efficiency. This advantage makes polymer cells widely used in polar scientific research equipment and aerospace fields.
Traditional liquid electrolyte lithium batteries have hidden dangers such as easy leakage and poor thermal stability, especially in scenarios with strict safety requirements such as smartphones and electric vehicles, where their limitations are becoming increasingly prominent. As a representative of third-generation lithium battery technology, polymer lithium batteries not only solve the safety pain points of traditional lithium batteries by replacing liquid electrolytes with solid polymer electrolytes, but also achieve breakthroughs in lightweight and shape customization.
3、 Comparison of application scenarios between polymer lithium batteries and lithium batteries
1）. Consumer Electronics: Lightweight and Innovative Forms
Smartphones and wearable devices require extremely high flexibility in battery form. Polymer lithium batteries can be made into cylindrical, square, or irregular structures. For example, a certain brand of foldable screen mobile phone uses bipolar ear polymer cells to achieve a design with a screen bending radius of less than 3mm. On the other hand, traditional lithium batteries are limited by hard shell packaging and difficult to adapt to flexible display technology.
2）. Electric Vehicles: Balancing Range and Fast Charging Techniques
Although mainstream electric vehicles still use liquid ternary lithium batteries, leading companies have accelerated the layout of polymer systems, such as CTP (Cell to Pack) polymer battery packs. By removing the module structure, the volume utilization rate is increased by 15%, and the system energy density exceeds 200Wh/kg. In addition, the low impedance characteristics of polymer electrolytes support 4C fast charging technology, which can complete 80% energy replenishment in 15 minutes.
3）. Energy storage and cutting-edge fields
In grid level energy storage scenarios, modular design of polymer lithium batteries can reduce thermal management costs. In the medical field, its biocompatibility advantage drives the upgrade of implantable devices such as pacemakers and artificial hearts. In contrast, traditional lithium batteries are limited in their application in medical settings due to electrolyte toxicity issues.
What is the difference between polymer lithium batteries and lithium batteries?
4、 Cost and Industrialization: The Breakthrough Path of Polymer Lithium Batteries
Although polymer lithium batteries have significant advantages, their cost is about 20% higher than liquid batteries. This is mainly due to the complex high-purity synthesis process of solid electrolyte materials (such as sulfides) and the lack of widespread large-scale production equipment. However, with the breakthrough of dry electrode technology and solid-state electrolyte coating process, the cost has shown a downward trend. According to Bloomberg NEF's prediction, the cost of polymer lithium batteries is expected to drop below $100/kWh by 2028, leading to an explosion in high-end markets such as electric aviation and deep-sea exploration.
5、 Market selection and future prospects under the technological revolution
The current relationship between polymer lithium batteries and liquid lithium batteries is not a complete replacement, but complementary coexistence. In the mainstream electric vehicle market, liquid batteries still dominate due to their mature industrial chain; In the segmented fields of high-end consumer electronics, aerospace, etc., polymer lithium batteries have become the leading choice due to their safety and degree of freedom of form. The integration of semi-solid batteries, silicon-based negative electrodes, and other technologies may make polymer lithium batteries the intermediate state of the next generation of energy storage technology, promoting the evolution of the global energy structure towards higher density and safety.
6、 How to choose between regular lithium batteries and polymer lithium batteries?
The former is common in cheap electronic products, with a hard shell but average battery life; The latter is mostly used for high-end devices, as thin as cards and with longer battery life. There are three key differences:
① Safety - Polymer batteries cannot explode or burn, making them more reliable in extremely harsh environments;
② Charging speed - supports 200W fast charging, which is twice as fast as regular lithium batteries;
③ Freedom of form - bendable and foldable, suitable for new forms of devices such as smart watches and AR glasses.
Although the price is 30% higher, the 6000 cycle life (about 500 cycles for regular lithium batteries) makes long-term use more cost-effective. Consumers who pursue quality and safety are advised to choose polymer batteries. For consumers, understanding the differences between the two can help them make rational decisions when choosing devices; For the industry, grasping the technological dividends of polymer lithium batteries will be a key chip in winning the era of carbon neutrality.
What is the difference between polymer lithium batteries and lithium batteries? The lithium battery industry is undergoing a polymer technology revolution: ① In terms of cost structure, cobalt removal and dry electrode processes have reduced the material cost of polymer batteries by 25%, but increased manufacturing equipment investment by 40%; ② In terms of application scenarios, its 2.1mm ultra-thin feature captures 80% of the market share of wearable devices, while high security drives the penetration rate of energy storage in the power grid from 15% to an expected 65% by 2025; Although liquid lithium batteries still dominate the low-end market, the annual performance improvement of polymer systems by 15% is accelerating the restructuring of the industry landscape.
