Tech Features

High-voltage EV battery packs: benefits and challenges. More voltage, more better?

In 2020, Porsche delivered just over 20,000 units of its luxury Taycan EV—the first vehicle from a major automaker to sport an 800 V (nominal) battery, which is more than double the voltage of its competitors (and firmly into light-rail and switchyard locomotive territory, actually). It appears that many other EVs will soon follow in… Read more »

Is aviation the best application yet for hydrogen fuel cells?

Q&A with ZeroAvia CEO Passenger cars are well on their way to going electric, and the path to a big market share for heavy-duty EVs such as buses and delivery trucks is becoming clearer. However, aviation remains a new frontier for zero emissions. There are several new powertrain options, and none has yet proven itself… Read more »

Isolation technologies for EV power electronics

A previous article on bidirectional chargers touched on using transformers to provide isolation at high power levels—in which application they are the only game in town, really—but this time the focus will be on achieving isolation at low power levels, such as the feedback signal in a regulator, data communication buses between devices, gate drivers… Read more »

Setting a new standard for battery leak testing

Defective cells can shorten battery life, decrease range, and lead to safety issues. A leaky cell housing, one common failure mode for Li-ion batteries, can allow ambient humidity to come in contact with the electrolyte, triggering an exothermic (heat-releasing) chemical reaction.  Currently, the common practice in the battery manufacturing industry is to test cell packaging… Read more »

Proterra beefs up its battery expertise: Q&A with CTO Dustin Grace

Since its founding in 2004, Proterra has grown to become North America’s largest supplier of electric buses. The company has sold some 950 buses to transit agencies, airports, universities, national parks and private companies in 43 states and provinces. Under its Proterra Powered program, the company provides powertrains to other vehicle makers—school buses for Thomas… Read more »

A closer look at the DC Link

The term DC link has traditionally referred to the junction between two power conversion stages where an energy storage element (almost always a capacitor) acts as a buffer for each.  A classic example is the capacitor placed between the rectifier and the voltage source inverter in a mains-supplied variable frequency drive (see Fig. 1). This… Read more »

The technical challenges of bidirectional chargers

For years, we’ve been hearing about an EV technology that promises to be a game-changers: Vehicle-to-Grid (V2G) bidirectional charging. My recent work with one V2G charger developer, Fermata Energy, has convinced me that V2G has found its proverbial killer app: load peak shaving for commercial/industrial energy customers. This article is going to concentrate on the… Read more »

Li-Cycle recovers usable battery-grade materials from shredded Li-ion batteries

Q&A with CEO Ajay Kochhar It’s usually one of the first objections cited by EV naysayers: batteries can’t or won’t be recycled, and they contain hazardous materials that will end up in landfills. In fact, no such sinister scenario is likely—most of the components of Li-ion batteries are valuable, and it’s quite feasible, technically and economically,… Read more »

Scale up micro-solid-state batteries to large EV cells? It’s not so simple.

Q&A with Ilika Technologies Every other scientist in the battery world seems to be working on commercializing large-scale solid-state batteries for use in EVs. The potential for technical and safety benefits is substantial, so there will be a big pot of gold for those who first make real advancements on the automotive level.  Using solid… Read more »

Specialized motor materials and constructions (Part 2)

The previous article in this two-part series looked at specialized materials that are (or will be) used in motors; the focus this time will be on the innovative methods of construction that make motors more suitable for EV traction applications. Separating the wheat from the chaff is especially important here, because hyperbole (and outright fantasy)… Read more »