3M Lithium Ion Battery Material and Solution for EV and Energy Storage Application
3M Company is committed to providing high quality products and services to our customers to enable our customers to develop high quality products. In this presentation, we first share the potential application of 3M product Novec 1230 in the lithium-ion battery pack to improve its safety. Then we will discuss more on the 3M cathode status and new developments. We also cover 3M Si-alloy anode and 3M advanced high-voltage electrolyte.
In the battery pack for EV and HEV where a large number of lithium-ion batteries are used in the battery pack via serial or parallel connection, a safety issue is raised. The internal short inside the single battery via external force or from internal metal particle impurity cannot be avoided 100% completely. Once it happens, the whole battery pack may go into thermal runaway and produce fire. Several famous examples of this are published in consumer products every year.
3M is a major manufacturer of fluorinated chemicals. Novec 1230 was commercialized for fire protection. In this disclosing, we will report the benefits of the Novec 1230 to safety of the lithium-ion battery pack.
A set of 2.0Ah 18650 type lithium-ion batteries based on the LiCoO2/graphite chemistry were used to make 3P2S battery pack. The AC impedance at 1KHz for the single 18650 cell was about 40mOhm. Nail penetration was used to internally short a single 18650 causing thermal runaway in the 3P2S battery pack. We compared the response of the battery pack and its cell skin temperatures for one pack immersed in Novec 1230 to the another without Novec 1230. Fig 1 is the top view of the test device including the solvent container, 3P2S lithium ion battery pack and the position of the thermal couples. The Cell T0 was shorted at the location “X”. Without Novec 1230, after the cell T0 thermally runs away, the Cell T1 and T2 thermal runs away in about a 2.5mins interval, one by one. Flames were observed. The cell skin temperature reached more than 600oC. With immersing into about 300cc of Novec 1230, after cell T0 thermally runs away, all other cells never reach a temperature higher than 60oC It is very clear that Novec 1230 dramatically reduced the chance of the thermal runaway of the battery pack.