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What's graphene battery?

2022-08-30

What is graphene battery?



Graphene battery is a new development prospect of lithium battery. Graphene battery technology has always been the focus of our attention.






Advantages of graphene in lithium battery



Graphene plays a role in enhancing heat dissipation in the lithium battery, rather than adding graphene to the positive and negative electrodes of the lithium battery. Therefore, graphene in the battery will not increase the charge and discharge rate, nor increase the energy density, nor improve the conductivity. It is a lithium battery. For example, Huawei has produced a lithium battery with better heat dissipation performance. The graphene layer realizes heat dissipation.





Why should lithium batteries enhance heat dissipation?



Will the heat dissipation be enhanced when the mobile phone chip is fully loaded? No, what is the temperature of the mobile phone? The full load operation time of the mobile phone chip accounts for less than 1% of the use time of the mobile phone. Mobile phones and other civil electronic devices are typical applications at low temperatures, and ordinary lithium batteries do not need additional improvement. However, the temperature in some places is very high. For example, a base station near the equator has a backup battery working environment of 50 ° C. For ordinary lithium batteries, this temperature is on the verge of collapse. In the past, only batteries with larger capacity on the scalp could meet the requirements of charging and discharging cycles. The effect of temperature on the battery is mainly to accelerate the evaporation of water in the electrolyte. In this Huawei battery, water is completely removed from the electrolyte formulation and a graphene heat dissipation layer is used. The heat generated when the battery is charged and discharged is easier to output. Huawei provides a set of performance data, that is, after 2000 cycles of charging and discharging at 60 ° C, the capacity remains at 70%, and the capacity loss is less than 13% after 200 days of storage at 60 ° C.





Development prospect of graphene battery



This data may not be unknown to people in the lithium battery industry. If we put ordinary mobile phone batteries at this ambient temperature, that is, 60 ℃, most batteries will not work properly. Since most of the lithium batteries of mobile phones are ternary materials with high energy density, they are not suitable for working at high temperatures. There is a lithium iron phosphate battery that can work at high temperatures, but this rarely happens in mobile phone batteries. And the lithium iron phosphate battery is also a battery having many cycles. For example, a lithium battery can be charged and discharged 2500 times on average, and it will drop to 300 times at 60 ° C. Huawei can also maintain it 2000 times. In addition, the battery will cause electrolyte loss at high temperature. Generally, lithium iron phosphate is stored at 60 ° C for 7 months with a capacity loss of 40% - 50%. This is not surprising, but Huawei lost only 13%.





Application: because graphene battery has the characteristics of high conductivity, high strength, ultra-thin and ultra-thin, as well as very high performance improvement at high temperature, graphene battery can not only be used in base stations, but also in potential application fields such as unmanned aerial vehicles, aerospace military industry or new energy vehicles, and will also play an important role.