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An Empirical Model for the Design of Batteries with High Energy Density
journal contribution
posted on 2020-02-18, 18:37 authored by Yingqiang Wu, Leqiong Xie, Hai Ming, Yingjun Guo, Jang-Yeon Hwang, Wenxi Wang, Xiangming He, Limin Wang, Husam N. Alshareef, Yang-Kook Sun, Jun MingThe
development of rechargeable batteries beyond 300 Wh kg–1 for electric vehicles remains challenging, where
low-capacity electrode materials (especially a graphite anode, 372
Ah kg–1) remain the major bottleneck. Although many
high-capacity alternatives (e.g., Si-based alloys, metal oxides, or
Li-based anode) are being widely explored, the achieved energy density
has not exceeded 300 Wh kg–1. Herein, we present
a new empirical model that considers multiple design parameters, besides
electrode capacities, including areal loading density, voltage difference,
initial capacity balance between the anode and cathode, and initial
Coulombic efficiency, to estimate the achievable energy density. This
approach is used to predict battery design that can achieve an energy
density of >300 Wh kg–1. The model reveals that
the lithium storage capacity of electrode materials is only one of
several important factors affecting the ultimate battery energy density.
Our model provides a new way to review the current battery systems
beyond the prism of the electrode capacity and also presents a straightforward
guideline for designing batteries with higher energy densities.