Discussion on the safety and economic cycle life of 280Ah lifepo4 cell

    Many customers have many questions about Lifepo4 Cell, most of which are about safety, number of cycles and economic benefits of the project.

    The external publicity of battery cell manufacturers generally refers to economic cycle life of 6,000, 8,000, and 12,000 times, which is the result of derivation in a specific experimental environment and data model.

When the battery cell is PACKed into a battery pack, and the battery pack is used in the energy storage system, its economic cycle life is a question that the industry is subjectively and objectively reluctant to mention; because this will shake everyone's confidence in the energy storage business model.

    Taking the mainstream product lifepo cell 280AH square aluminum shell battery as an example, we will discuss:

    1. Safety：In the second half of 2022, Ouyang Minggao, an academician of the Chinese Academy of Sciences, warned that the explosion index of lithium iron phosphate in large-capacity batteries is twice that of ternary materials; and called on the industry to use 280AH batteries as the ceiling of large batteries, and not to increase the capacity.

As a call made by a top scientist in the industry, everyone turned a deaf ear to it. Larger capacity batteries emerge in an endless stream and become larger and larger; the entire industry is like a train that cannot be stopped, continuing to run blindly; embarking on the evil path of pursuing energy density and ignoring the safety of batteries.

    2. Economic cycle life：The economic cycle life of 280AH batteries reaches 6,000 times and exceeds 6,000 times. Each battery manufacturer has set prerequisites.

    A Working temperature, 25°C±2°CB Initial clamping force 300KGF Wrapping battery C Depth of charge and discharge, 80-90%D Charge and discharge rate 0.2C-0.5C.

    After 6000 cycles, the remaining capacity is 70-80%. The specific information depends on the product specifications of each manufacturer; as for those with a remaining capacity of about 60% after 8000 cycles, it is meaningless to estimate the remaining capacity of those that exceed 10,000 cycles. This is just a gimmick promoted by the manufacturer.

    The number of cycles of a single cell is not particularly significant for the number of cycles of an energy storage power station; a single cell can only be charged and discharged as part of an energy storage cabinet after being PACKed into a battery pack.

    The three indicators of voltage, capacity, and internal resistance are the key indicators of cell matching.

    The 280AH square aluminum shell cell will be put into use on a large scale in 2021-2022. If we assume that the economic cycle service life of 3000 times is established, the first batch of 280 cells will be installed around 2025, and there will be a sharp increase in after-sales incidents. Everything needs time to verify.