With the rapid development of the socio-economy, lithium polymer batteries have ensured both safety and cycling performance of lithium secondary batteries. They are known for their high energy density, wide operating temperature range, stable working voltage, and long storage life. As a result, they are hailed as “the most promising chemical power source”. Currently, many research institutions in China have conducted extensive research and development work on lithium polymer batteries, achieving certain results in the preparation of polymer electrolytes and battery formation processes.
What is Small Lipo battery?
Small Lipo batteries have a high energy density, with a capacity 1.5 to 2.5 times greater than that of nickel-hydrogen or nickel-cadmium batteries, or even higher. They can be made thinner due to their smaller thickness. Traditional liquid lithium batteries are fabricated by first customizing the outer shell and then inserting the positive and negative electrode materials. Small Lipo batteries face a technological bottleneck in achieving a thickness below 3.6mm, but this is not an issue for polymer cells, which can be made thinner than 1mm, meeting the demand for ultra-thin smartphones.
Small Lipo batteries have a higher operating voltage for individual cells, ranging from 3.6V to 3.8V, far surpassing the 1.2V voltage of nickel-hydrogen and nickel-cadmium batteries. They are lightweight as well. Battery cells using polymer electrolytes do not require a metal casing as protective packaging. Small Lipo batteries are 40% lighter than steel-cased lithium batteries of the same capacity and 20% lighter than aluminum-cased batteries. In terms of capacity, Small Lipo batteries offer a 10-15% increase compared to steel-cased batteries of the same size specification, and a 5-10% increase over aluminum-cased batteries.
Small Lipo batteries have low self-discharge and experience minimal capacity loss after being stored for extended periods of time. The shape of Small Lipo batteries can be customized, allowing manufacturers to deviate from standard form factors and economically produce batteries of suitable sizes. Small Lipo batteries can have their cell thickness increased or decreased according to customer demands, enabling the development of new cell models. They have the advantage of being cost-effective, with short molding cycles. Some can even be tailored to fit the shape of a specific phone, maximizing space utilization and enhancing battery capacity.
Small Lipo batteries exhibit excellent discharge characteristics due to their colloidal electrolyte. Compared to liquid electrolytes, colloidal electrolytes offer stable discharge behavior and higher discharge plateaus.
The design of protection boards for Small Lipo batteries is simple. Due to the use of polymer materials, the cells are not prone to fire or explosion, possessing inherent safety features. They have a long lifespan, with a cycle life of over 500 cycles under normal usage. There is no memory effect, so it is not necessary to fully discharge the remaining charge before recharging. Small Lipo batteries are convenient to use and do not require several hours of continuous charging to “activate” before use. They also have good safety performance. Polymer lithium-ion batteries adopt an aluminum-plastic soft packaging structure, which differs from the metal casing of liquid-state cells. In case of safety hazards, liquid-state cells are prone to explode, while polymer cells may only swell. Additionally, Small Lipo batteries produced by fpbattery comply with strict international industry standards and have gained popularity among consumers both domestically and internationally.
Typical Application of Small Small Lipo battery
Compared to other types of batteries, small lithium Small Lipo batteries have higher energy density. This means they can provide longer usage time and more power output, allowing e-cigarettes to be used for extended periods. E-cigarettes typically require frequent charging to ensure their normal operation. Small lithium Small Lipo batteries have excellent rechargeability and can withstand multiple charge-discharge cycles without significant capacity loss. This allows users to conveniently charge their e-cigarettes using charging devices. Small lithium Small Lipo batteries support fast charging technology, which means users can fully charge the battery in a shorter amount of time. This is particularly important for users who are in urgent need of charging or have limited time.
Small lithium Small Lipo batteries are relatively compact and lightweight, making them suitable for integration into e-cigarette devices. E-cigarettes often require compact designs for convenient portability and use. The application of small lithium Small Lipo batteries in e-cigarettes usually includes multiple layers of protection measures. These protective measures can prevent overcharging, over-discharging, overcurrent, and short circuits, thereby providing higher safety performance and reducing the risk of fires and other accidents.
Smart glasses often require long periods of use, including video watching, internet browsing, navigation, and other smart functionalities. Small lithium Small Lipo batteries, with their high energy density, can provide extra power reserves, allowing smart glasses to be used for longer durations after a single charge. The design of smart glasses aims for lightweight and portability to provide a better wearing experience. Small lithium Small Lipo batteries are relatively small and lightweight, making it convenient to embed them into the frame of smart glasses without adding too much weight burden.
Due to the frequent usage of smart glasses, users desire quick charging to minimize waiting time. Small lithium Small Lipo batteries support fast charging technology, enabling fast charging through specific chargers, thus reducing charging time and enhancing user convenience. Small lithium Small Lipo batteries offer reliable power supply, ensuring the stability of smart glasses during usage. This means that users can enjoy various functionalities whenever needed without worrying about battery depletion or inadequate power supply.
The application of small lithium Small Lipo batteries in smart glasses typically incorporates multiple layers of protection measures, such as overcharging, over-discharging, overcurrent, and short circuit protection. These protective measures can reduce the risk of battery failure and unexpected accidents, ensuring user safety.
Small Lipo Battery Application in General
Portable Medical Devices: Small lithium Small Lipo batteries play a crucial role in portable medical devices. For example, portable defibrillators, blood glucose monitors, ventilators, and infusion pumps all utilize this type of battery. They provide reliable power supply, ensuring the normal operation of these devices in emergency or mobile environments.
Drones and Aviation Models: The high energy density and lightweight features of small lithium Small Lipo batteries make them the preferred battery type for drones and aviation models. These batteries can provide sufficient power, enabling drones to fly for extended periods and withstand high-power output requirements.
Portable Lighting Devices: Small lithium Small Lipo batteries are widely used in portable lighting devices such as flashlights, headlamps, and camping lanterns. These batteries offer long battery life, providing reliable brightness and illumination.
Wearable Devices: With the rise of wearable devices, small lithium Small Lipo batteries find extensive application in devices like smart wristbands, smart glasses, and health monitors. These batteries not only provide stable power but also have sizes and weights that conform to ergonomic design principles.
Adaptation of Lipo Battery Temperature Environment
The temperature adaptation of Small Lipo batteries is crucial for their safe use in different environmental conditions. Among all factors, temperature has the greatest impact on the charging and discharging performance of Small Lipo batteries. The electrochemical reactions at the electrode/electrolyte interface are temperature-dependent, which is considered the “heart” of the Small Lipo battery. If the temperature decreases, the reaction rate at the electrode also decreases, resulting in a lower discharge current and a decrease in power output. Conversely, an increase in temperature leads to higher output power. Temperature also affects the transport speed of the electrolyte, with faster transport at higher temperatures and slower transport at lower temperatures, thereby impacting the charging and discharging performance of the Small Lipo battery. However, excessively high temperatures can disrupt the chemical balance inside the Small Lipo battery.
After the battery is assembled and filled, it undergoes an initial activation charge, known as formation, at a specified temperature of 45±5°C.
After a period of rest following formation, a capacity test is conducted by charging the battery. The specified temperature for the capacity test is 35±5°C.
The storage temperature of the battery is generally room temperature, around 25±5°C. Temperature affects the activity of lithium ions, with higher temperatures increasing activity. However, temperatures exceeding 60°C can cause irreversible damage to the internal separator of the Small Lipo battery, rendering it unusable. Extremely low temperatures result in reduced activity of lithium ions, leading to decreased battery capacity. This is why fully charged phones indoors may lose power and fail to make calls outdoors during winter in northern regions. However, the battery recovers once returned to normal temperature, and the impact is not significant. When the battery is used at 35°C, its capacity is relatively higher. As the temperature rises further, the effect on capacity becomes relatively smaller, while temperatures above 60°C can potentially damage the battery and affect its lifespan. Extremely low temperatures can also result in lower capacity, meaning that some of the battery’s power cannot be utilized. Overall, the difference in capacity during normal battery usage under different temperatures is not significant. For example, for a lithium iron phosphate cell, the capacity at 20°C is only about 0.95% lower than at 45°C, which is less than 1%.
Future Development Of LiPo Battery
The future technological development direction of Small Lipo batteries is towards solid-state batteries. Recently, scientists in the United States announced the development of a solid-state lithium-sulfur battery, which is a solidified version of liquid lithium-ion batteries and can improve energy density. However, the performance of Small Lipo batteries has not yet reached the level of solid-state batteries. The energy density target for solid-state batteries is 400Wh/kg, with a cycle life of 3,000 cycles (10 years). This technology aims to significantly improve rate performance, capacity, and safety, thereby enabling Small Lipo batteries to have both high-capacity and high-rate advantages.
The first requirement for solid-state batteries is the solidification of electrolytes. Currently, many domestic “polymer” batteries use liquid electrolytes in flexible packaging, which are referred to as Small Lipo batteries with flexible packaging in foreign countries. The electrolyte materials and additives in solid-state batteries should enhance electrochemical performance and thermal stability. Another purpose of using additives is to ensure that the heat dissipation and conductivity of the battery are not affected by the solid state.
Small Lipo batteries have several obvious advantages, such as high energy density, smaller size, ultra-thinness, lightweight, high safety, and low cost, which make them increasingly used in various aspects of societal life. The future development direction of Small Lipo batteries is towards solid-state batteries, which will greatly enhance their lifespan, rate performance, capacity, and safety.