Comparison of Lithium-Ion Anode Materials Using an Experimentally Verified Physics-Based Electrochemical Model

Rujian Fu,Xuan Zhou,Douglas Blaisdell,Rui Xiong,Ajay Jagadale,Hengbin Fan,Xi Zhang

doi:10.3390/en10122174

Abstract

Researchers are in search of parameters inside Li-ion batteries that can be utilized to control their external behavior. Physics-based electrochemical model could bridge the gap between Li+ transportation and distribution inside battery and battery performance outside. In this paper, two commercially available Li-ion anode materials: graphite and Lithium titanate (Li4Ti5O12 or LTO) were selected and a physics-based electrochemical model was developed based on half-cell assembly and testing. It is found that LTO has a smaller diffusion coefficient (Ds) than graphite, which causes a larger overpotential, leading to a smaller capacity utilization and, correspondingly, a shorter duration of constant current charge or discharge. However, in large current applications, LTO performs better than graphite because its effective particle radius decreases with increasing current, leading to enhanced diffusion. In addition, LTO has a higher activation overpotential in its side reactions; its degradation rate is expected to be much smaller than graphite, indicating a longer life span.

Highlights

Scientists around the world have been making extensive efforts to develop clean and efficient energy storage systems to enable renewable energy technologies to deal with critical contemporary energy issues such as diminishing fossil fuel reserves, increasing energy demand, and pollution of the environment
A physics-based electrochemical model was developed based on half-cell assembly and testing to simulate the performance of two common Li-ion battery anode materials
Unlike the traditional equivalent circuit model, there are more than 30 parameters involved when setting up an electrochemistry-based model

Summary

Introduction

Scientists around the world have been making extensive efforts to develop clean and efficient energy storage systems to enable renewable energy technologies to deal with critical contemporary energy issues such as diminishing fossil fuel reserves, increasing energy demand, and pollution of the environment. LIBs, since first commercialized by Sony in 1991, have quickly come to dominate the battery market for portable electronics including smartphones, laptops, digital cameras, etc., and are currently being developed and utilized for new emerging markets such as electrified vehicles (EV) and large-scale grid energy storage [1,2]. In most of these applications, a battery management system (BMS) consisting of both hardware and software is necessary. A BMS must be sophisticated when applied to EVs, because it is responsible for operating the battery

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