With the development of global diversification, our lives are constantly changing, including the various electronic products we come into contact with. Then you must not know some of the components of these products, such as high voltage lithium batteries.
As the capacity requirements of lithium-ion batteries for electrical equipment continue to increase, people have higher and higher expectations for lithium battery energy density. In particular, various portable devices such as smartphones, tablets, and laptops have put forward higher requirements for lithium-ion batteries that are small in size and have long standby time.
Similarly, other electrical equipment, such as energy storage equipment, power tools, electric vehicles, etc., are constantly developing lithium-ion batteries with lighter weight, smaller size, higher output voltage and power density. Therefore, high voltage lithium battery have also become an important research and development direction in the most top bess suppliers.
What is high voltage lithium battery?
High voltage battery refers to battery whose battery voltage is relatively high compared to ordinary batteries. It can be divided into two types according to battery cells and battery packs. High-voltage batteries are defined from the voltage of the battery cells. This aspect is mainly for lithium batteries. Currently, the main types of lithium battery cells are high voltage lithium battery cells and low voltage lithium battery cells.
Currently, lithium cobalt oxide has been widely researched and applied as a high-voltage anode material. This structure is non-nafeo2 type and is more suitable for the insertion and ejection of lithium ions. The theoretical energy density of lithium cobalt oxide is 274mAh/g, the production process is simple, the electrochemical performance is stable, and the market share is high.
In practical applications, only some lithium ions can be reversibly embedded and ejected, and the actual energy density is about 167mAh/g (working voltage is 4.35v). Increasing the operating voltage can significantly increase energy density. For example, increasing the operating voltage from 4.2v to 4.35v can increase the energy density by about 16%.
Background of high voltage lithium battery development
In order to design high-energy-density lithium-ion batteries, in addition to continuously optimizing their space utilization, increasing the compaction density and gram capacity of the battery’s positive and negative electrode materials, highly conductive carbon nanometers and polymer binders are used to improve the positive and negative electrodes. In addition to the active material content, increasing the operating voltage of lithium-ion batteries is also one of the important ways to increase battery energy density.
The cut-off voltage of lithium-ion batteries is gradually transitioning from the original 4.2V to 4.35V, 4.4V, 4.45V, 4.5V and 5V. Among them, 5V nickel-manganese lithium-ion batteries have excellent characteristics such as high energy density and high power and will be one of the important directions for the future development of new energy vehicles and energy storage. With the continuous development of power supply R&D technology, lithium-ion batteries with higher voltage and higher energy density will gradually come out of the laboratory and serve consumers in the future.
Characteristics of high voltage lithium battery
High voltage lithium battery cells have higher energy density and lower safety performance than low-voltage batteries, but their discharge platform is relatively high. At the same battery capacity, high-voltage batteries are lighter than low-voltage batteries in terms of volume and weight.
As the voltage of high voltage lithium battery increases, some safety properties will be reduced during use, so they have not been used in bulk in power vehicles. At present, the battery cathode materials used in power vehicles are mainly ternary materials and lithium iron phosphate. In order to increase energy density to meet demand, high-nickel cathode materials such as 811NCM and NCA, high-capacity silicon-carbon anodes, or improving battery space utilization are generally selected to improve energy density and battery life cycle.
Current and high voltage lithium cobalt oxide materials are used in high-energy-density batteries, such as high-end mobile phone battery manufacturers. Increasing battery performance requirements are mainly reflected in the need for higher energy density, such as carbon requirements for 4.35V battery cathodes. The energy density is about 660wh/L, and the 4.4V battery has reached about 740wh/L.
This requires the anode material to have a higher compaction density, a higher void volume, and the material’s structure to be better stable under high pressure. However, the lithium cobalt oxide electrode material has shortcomings such as lack of cobalt resources, high price, and certain toxicity of cobalt ions, which limits its wide application in power lithium batteries.
In terms of discharge rate between high-voltage batteries and low-voltage batteries, high voltage lithium battery has a higher discharge rate and stronger power than low-voltage lithium battery. Therefore, high-voltage battery cells should theoretically be more suitable for use in products and equipment that require high-rate discharge.
Precautions for using high voltage lithium batteries
The voltage of lithium batteries is generally between 3.7V and 3.8V. Lithium batteries can be divided into low-voltage lithium batteries and high-voltage lithium batteries according to voltage. The rated voltage of low-voltage lithium batteries is generally below 3.6V, and the rated voltage of high-voltage lithium batteries is generally above 3.6V.
According to the lithium battery meter test, the voltage range of low-voltage lithium batteries is 2.5~4.2V, and the voltage range of high-voltage lithium batteries is 2.5~4.35V. The voltage level is also one of the important signs to distinguish the two.
High-voltage lithium batteries are suitable for applications that require high battery capacity, volume, and weight, such as smartphones, tablets, and laptops; low-voltage lithium batteries are suitable for applications that do not require high volume and weight, such as power tools.
At the same time, you need to pay attention to the following things when using high-voltage lithium batteries:
1. During use, a special battery charger should be used, and attention should be paid to the battery charging voltage and current parameters;
2. Do not forcibly short-circuit the lithium battery to avoid damaging the battery and causing safety issues;
3. Do not randomly select batteries for mixed use. Batteries with the same parameters should be selected for combined use;
4. When lithium batteries are not in use, they should be stored in a cool and dry location.
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