Methodology for the Optimisation of Battery Hybrid Energy Storage Systems for Mass and Volume Using a Power-To-Energy Ratio Analysis

Abstract

Increasingly stringent emission regulations and environmental concerns have propelled the development of electrification technology in the transport industry. Yet, the greatest hurdle to developing fully electric vehicles is electrochemical energy storage, which struggles to achieve profitable specific power, specific energy and cost targets. Hybrid energy storage systems (HESSs), which combine energy- and power-optimised sources, seem to be the most promising solution for improving the overall performance of energy storage. The potential for gravimetric and volumetric reduction is strictly dependent on the overall power-to-energy ratio (PE ratio) of the application, packaging factors, the minimum and maximum PE ratio achievable for the system’s energy- and power-optimised sources and the performance of power electronics. This paper presents a simple optimisation methodology that considers these factors and identifies the optimal HESS requirements that may present new opportunities for a variety of vehicles where low weight and volume are of high importance. The simplicity of the method means that decisions relating to a HESS can be made earlier in the system design process. This method of analysis showed that a battery HESS has the potential to reduce cell mass and volume by over 30% for applications that are well suited to optimal HESS characteristics.

A Critical Comparison of the Cuk and the Sheppard–Taylor Converter

“…Figure 4 shows the equivalent circuit of the Cuk converter when the MOSFET is off. The state-space model of this circuit is represented in (2).…”

“…In addition, international agreements to reduce the environmental impact of power generation have been established, such as the Kyoto protocol. Therefore, there are significant projects related to clean energy generation in almost every country [1,2]. According to the 2020 global status report of REN21, it is cheaper to generate power from solar panels than build new coal plants in most countries.…”

Benchmarking the ragone behaviour and power performance trends of pseudocapacitive batteries

“…the top right corner of figure 1(a)). However, the theoretical properties that impede or enable performance in this long-sought domain are not entirely understood [14][15][16][17]. The two energy storage systems closest to reaching this ultimate goal are batteries and supercapacitors [18][19][20][21].…”

Battery Electrolyte Design for Electric Vertical Takeoff and Landing (eVTOL) Platforms

“…[ 7 ] In addition, the pareto front dictates that high energy density systems come at the cost of the power density due to the transport limitations in high‐loading cathodes (Figure S1b, Supporting Information). [ 8 ] One factor of interest in eVTOL applications is the discharge current, defined as the ratio of energy density to power density of the battery system. For efficient hovering, a high discharge current (1 C–20 C) is needed, while a low discharge current (C/3‐1C) is required for cruising.…”