The energy revolution requires coordination in energy consumption, supply, storage and institutional systems. Renewable energy generation technologies, along with their associated costs, are already fully equipped for large-scale promotion. However, energy storage remains a bottleneck, and solutions are needed through the use of electric vehicles, which traditionally play the role of energy consumption in power systems. To clarify the key technologies and institutions that support EVs as terminals for energy use, storage, and feedback, the CSEE JPES forum assembled renowned experts and scholars in relevant fields to deliver keynote reports and engage in discussions on topics such as vehicle–grid integration technology, advanced solid-state battery technology, high-performance electric motor technology, and institutional innovation in the industry chain. These experts also provided prospects for energy storage and utilization technologies capable of decarbonizing new power systems.

Fluorinated electrolytes possess good antioxidant capacity that provides high compatibility to high-voltage cathode and flame retardance; thus, they are considered as a promising solution for advanced lithium-ion batteries carrying both high-energy density and high safety. Moreover, the fluorinated electrolytes are widely used to form stable electrolyte interphase, due to their chemical reactivity with lithiated graphite or lithium. However, the influence of this reactivity on the thermal safety of batteries is seldom discussed. Herein, we demonstrate that the flame-retardant fluorinated electrolytes help to reduce the flammability, while the lithium-ion batteries with flame-retardant fluorinated electrolytes still undergo thermal runaway and disclose their different thermal runaway pathway from that of battery with conventional electrolyte. The reduction in fluorinated components (e.g., LiPF₆ and fluoroethylene carbonate (FEC)) by fully lithiated graphite accounts for a significant heat release during battery thermal runaway. The 13% of total heat is sufficient to trigger the chain reactions during battery thermal runaway. This study deepens the understanding of the thermal runaway mechanism of lithium-ion batteries employing flame-retardant fluorinated electrolytes, providing guidance on the concept of electrolyte design for safer lithium-ion batteries.

This paper presents an analysis of the dynamic response of a low pressure proton exchange membrane (PEM) fuel cell stack to step changes in load, which are characteristic of automotive fuel cell system applications. The goal is a better understanding of the electrical and electrochemical processes when accounting for the characteristic cell voltage response during transients. The analysis and experiment are based on a low pressure 5 kW proton exchange membrane fuel cell (PEMFC) stack, which is similar to those used in several of Tsinghua’s fuel cell buses. The experimental results provide an effective improvement reference for the power train control scheme of the fuel cell buses in Olympic demonstration in Beijing 2008.

A two-dimensional, steady-state, isothermal water-management model for a complete proton exchange membrane fuel cell (PEMFC) was developed. The model includes the transport in the diffusion layer and the proton exchange membrane (PEM) with a pseudo-homogeneous model for the cathode catalyst layer. The predicted fuel cell performance with variable cathode porosities compares well with experimental results. The model is then used to investigate the effects of some structural parameters, such as the rib size, the interdigitated flow field, and various operating conditions including the gas flow rate, the cell temperature and pressure, humidification, and the relative humidity at the inlet. Water management is best achieved by tuning the anode operating conditions.