The effect of cross-talk on performance of Li ion batteries and exploiting it for developing high performance Si-based batteries.

초록

Cross-talk in Li ion batteries can be defined as the chemical or electrochemical reactions at one electrode affecting the properties of the electrode. Cross-talk in conventional graphite anode-based batteries has been shown to be very detrimental to cell performance such as safety, cycle lifetime, calendar lifetime. For example, the dissolution of transition metal ions from the cathode and their deposition on the graphite anode is one of the most representative crosstalk behaviors, and it’s been widely reported that these deposited transition metal ions lead to impedance rise and electron conduction, resulting in surface parasitic reactions, cracking and pores in the structure of SEI layers of graphite anode.1-7 However, graphite anode has been being substituted by Si anode as the demand for high energy density batteries increases. Therefore, we will face new questions for the Si-based batteries: 1) how does crosstalk work in Si-based batteries? 2) what is the effect of crosstalk on cell performance in Si-based batteries? In this talk, I will present overview of crosstalk in conventional graphite- and Si-based batteries. And I will discuss our recent results showing that crosstalk in Si-based batteries is remarkably different from that in the - graphite-based batteries and has unexpected beneficial effects to stabilize the SEI of the Si anode.8,9 Therefore, crosstalk should be re-addressed in Si-based batteries and exploiting crosstalk in Si-based batteries can be a key for stabilizing the SEI of Si and developing high performance Si-based batteries.