The year 2021 is well known as the "1^st Carbon-Neutral Year". As a pioneer of carbon-neutral, the development of the lithium battery industry has also seen an "acceleration" this year. Mr. Song Huajie, Director of small power cylindrical battery of BAK, recently delivered the latest progress and leading advantages of BAK small power cylindrical battery development at a recent conference.

Song Huajie, Director of small Power cylindrical battery of BAK

Mr. Song Huajie said: “High energy density, long cycle life, high rate, fast charging, strong temperature adaptability, and high safety are the six major advantages of BAK small power cylindrical battery. In terms of improving battery capacity, BAK leads the industry with R&D and application progress, taking the lead in increasing the nickel content of ternary material to Ni88, realizing mass production and batch supply."

As four main materials of lithium battery, anode, cathode, separator and electrolyte determine the basic performance of lithium battery. Each increase in nickel content puts forward higher requirements on the material selection, proportion, and structure design of these four main materials.

When the nickel content is more than 0.8, the cathode material is easy to crack after cycling. BAK chooses coated and doped cathode materials to restrain cracking during cycling, thereby effectively improving battery life and safety performance. It is not enough to rely on the anode alone, the matching of the cathode is also very important. In the early stage, the cathode material of the lithium battery was mainly made of graphite. BAK is the first to use silicon in the cathode of cylindrical battery in China.The silicon-oxygen material has developed from the first generation of silicon to the third generation silicon, increasing the first effect from 77% to 86%, basically matching the anode efficiency, and gradually increasing the utilization rate of the anode.

The separator mainly affects the path of lithium-ion migration and diffusion speed , and safety performance. BAK uses wet and high porosity ceramic membrane to effectively improve the rate performance and safety performance of cylindrical batteries. In terms of electrolyte, BAK has always insisted on independent R&D, BAK’s new lithium salt additive LiODFB can form a good interface film on both anode and cathode.

The breakthroughs in R&D of the four main materials has made BAK small power cylindrical batteries show industry leading advantages in six core performances: high energy density, long cycle life, high rate, fast charging, strong temperature adaptability and high safety. In terms of capacity, BAK continuously released 18650-3.35Ah and 18650-3.5Ah cells in 2021, breaking the domestic 18650 cell capacity limit twice, mainly used in high-end products of global industry giants. In addition, the BAK 21700-5.0Ah cell has been mass-produced, and the product performance leads the industry in an all-round way. The 21700-5.3Ah cell has also entered the pilot stage and will become the main product of BAK small power next year.  While maintaining high capacity, the cycle life of BAK small power ylindrical battery can still reach the excellent performance of 1000 cycles at room temperature and more than 70% at 45 ℃ for 1000 cycles. Fast charging performance has been paid a growing number of attention in the field of automotive electronics, and there are also very high requirements in the field of small power. Through the step charging system, the charging efficiency of BAK small power cylindrical battery can achieve more than twice that of traditional charging systems, and it has excellent fast charging and cycle performance.

The product development model of production generation, R&D generation, and reserve generation, which has always been deployed in advance for end products, has made BAK continue to lead the industry in battery performance and has promoted BAK to catch up and develop rapidly in the field of small power as well. Achieved double shipment and double sales performance. From manufacturing thinking to consumer thinking, BAK is promoting the upgrade of consumer experience and contributes to a better life with the continuous improvement of product performance.