低成本、持久耐用的电动汽车可再生电池的关键

Lithium-sulfur batteries have never lived up to their potential as the next generation of renewable batteries for electric vehicles and other devices. But ?SMU mechanical engineer Donghai Wang and his research team have found a way to make these Li-S batteries last longer -- with higher energy levels -- than existing renewable batteries.
锂硫电池作为电动汽车和其他设备的下一代可再生电池，一直未能发挥其潜力。但SMU机械工程师Donghai Wang及其研究团队找到了一种方法，可使这些Li-S电池比现有可再生电池寿命更长——且能量水平更高。

The research team has been able to prevent Li-S batteries from producing an unwanted side effect known as polysulfide dissolution that appears over time, shortening their lifespan.
研究团队已成功防止锂硫电池随时间推移产生一种名为多硫化物溶解的不良副作用，这种反应会缩短电池寿命。

"This breakthrough could lead to more durable, long-lasting batteries," said Wang, the Brown Foundation Chair of Mechanical Engineering and Professor of Mechanical Engineering at SMU Lyle. His research focuses on the design and synthesis of nanostructured functional materials and energy storage technologies like Li-ion batteries and also beyond Li-ion technology.
“这一突破有望带来更耐用、寿命更长的电池，”南方卫理公会大学莱尔机械工程系布朗基金会讲席教授王先生表示。他的研究专注于纳米结构功能材料的设计与合成，以及锂离子电池等储能技术，同时也涉及后锂离子技术领域。

A study published in the journal Nature Sustainability shows that the team's newly developed hybrid polymer network cathode allows Li-S batteries to deliver over 900 mAh/g (milliampere-hours per gram mass), compared to the typical 150-250 mAh/g capacity in lithium-ion batteries. That means it has a much higher amount of electrical energy it can preserve.
《自然-可持续性》期刊发表的一项研究显示，该团队新开发的混合聚合物网络阴极使锂硫电池可提供超过900 mAh/g（毫安时每克质量）的能量，而锂离子电池的典型容量仅为150-250 mAh/g。这意味着其电能储存能力（Ability）显著提升。

"It also offers excellent cycling stability -- outperforming conventional lithium-sulfur batteries," Wang said.
"它还提供了优异的循环稳定性——性能优于传统的锂硫电池，"王说。

Cycling capacity measures the number of times a battery can charge and discharge before its capacity degrades sharply. A higher cycling capacity means a longer-lasting battery.
循环能力衡量的是电池在容量急剧下降之前可以充放电的次数。循环能力越高，电池越耐用。

Assisting Wang with designing the cathode were researchers from Pennsylvania State University, Pacific Northwest National Laboratory, Brookhaven National Laboratory, University of Illinois at Chicago and the Argonne National Laboratory.
协助王设计阴极的研究人员来自宾夕法尼亚州立大学、西北太平洋国家实验室、布鲁克海文国家实验室、伊利诺伊大学芝加哥分校和阿贡国家实验室。

A cost-effective solution that delivers more energy
经济高效的解决方案，提供更多能量

What makes Li-S batteries so promising as a source of renewable energy is that they're more cost-effective and can hold more energy than traditional ion-based rechargeable batteries.
锂硫电池之所以有望成为可再生能源的来源，是因为它们比传统的离子充电电池更具成本效益且能储存更多能量。

But there is a key problem with these batteries.
但这些电池存在一个关键问题。

"Over the years, the battery community has struggled to mitigate the negative effects of polysulfide dissolution," Wang said.
多年来，电池领域一直致力于缓解多硫化物溶解带来的负面影响。

All batteries have a positive terminal and a negative terminal. Inside the battery, the chemical reaction that is continuously happening between these two terminals provides power or electricity to the battery.
所有电池都有一个正极和一个负极。在电池内部，这两个终端之间持续发生的化学反应为电池提供动力或电力。

In the case of Li-S batteries, a sulfur-containing positive electrode or terminal called a cathode is paired with a lithium metal negative electrode called an anode. In between those components is the electrolyte, or the substance that allows ions to pass between the two ends of the battery.
以锂硫电池为例，含硫的正极（称为cathode）与金属锂负极（称为anode）配对。两极之间是电解质（electrolyte），即允许离子在电池两极之间穿行的物质。

Yet, sulfur is far from an ideal material for an electrode.
然而，硫远非理想的电极材料。

When lithium ions bind with sulfur atoms at the cathode, they create soluble polysulfide molecules that drift into the electrolyte, causing degradation of the cathode and reducing the battery's ability to endure multiple charging cycles. This is known as polysulfide dissolution.
当锂离子在阴极与硫原子结合时，会形成可溶性多硫化物分子，这些分子扩散到电解质中，导致阴极退化并降低电池的Ability。这种现象被称为多硫化物溶解。

Wang and his team have found a way to fix this issue by using what they called a hybrid polymer network cathode.
王和他的团队利用他们称之为混合聚合物网络阴极的方法找到了解决这一问题的方法。

"Our cathode uses multiple sulfur bonding tethers, atomic adsorption, and fast Li-ion/electron transport at the molecular level," Wang explained. "This combination allows for real-time re-bonding and adsorption of any unbound sulfur species, thus effectively eliminating soluble polysulfides and extending the battery's cycle life."
王解释道："我们的阴极采用了多性向硫键束缚、原子吸附以及在分子层面实现快速的锂离子/电子传输。这种组合能够实时重新结合并吸附任何未结合的硫物质，从而有效消除可溶性多硫化物，延长电池的循环寿命。"