The 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.

中文翻译：

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高能量密度电池设计的经验模型

对于电动汽车而言，开发超过300 Wh kg ^–1的可充电电池仍然具有挑战性，其中低容量电极材料（特别是372 Ah kg ^–1的石墨阳极）仍然是主要瓶颈。尽管人们正在广泛探索许多高容量替代品（例如，硅基合金，金属氧化物或锂基阳极），但实现的能量密度并未超过300 Wh kg ^–1。在这里，我们提出了一个新的经验模型，该模型考虑了除电极容量以外的多个设计参数，包括面积负载密度，电压差，阳极和阴极之间的初始容量平衡以及初始库仑效率，以估算可实现的能量密度。该方法用于预测可实现> 300 Wh kg ^–1的能量密度的电池设计。该模型表明，电极材料的锂存储容量只是影响最终电池能量密度的几个重要因素之一。我们的模型提供了一种新的方式来查看电极容量以外的当前电池系统，并且为设计具有更高能量密度的电池提供了直接指南。