Infiniti has promised to build electric cars in fits and starts since 2012—but we're still waiting.

At the 2012 Detroit auto show, the upscale brand showed the Infiniti LE, a dressed up Nissan Leaf with a trunk, but it backed away from the model two years later and we didn't hear anything else about electrics from Infiniti for years.

Until now. This past January,the company announced that most new models coming from Infiniti would be electric starting in 2021. To go along with the announcement, the company rolled out its Q Inspiration concept sedan, showing what an Infiniti would look like on an electric-car platform.

Infiniti Q Inspiration, 2018 Detroit auto show

Infiniti Q Inspiration, 2018 Detroit auto show

Now, at the Beijing Auto Show taking place this week, the company has announced that a sedan based on the Q Inspiration will go into production by 2023, and that its platform will spawn a whole new line of Infiniti electric cars.

The design of the Q Inspiration is because electric cars done right require a different shape than gas-powered cars.

Instead of an engine in front—usually hanging out beyond the front wheels and creating a large front overhang—well-designed electric cars have a large battery pack under the floor that requires a long wheelbase to maximize its size and range. The battery pack may be several inches tall, giving electric cars a tall profile almost like an SUV.

Infiniti Q Inspiration, 2018 Detroit auto show

Infiniti Q Inspiration, 2018 Detroit auto show

That can make it harder for designers to make sedans or sports cars look as sleek as the Q Inspiration.

Infiniti Chairman and Global President Roland Krueger said the new format gives the Q Inspiration much bigger interior space than a conventional sedan of the same size—a key concern for Chinese buyers, where a production version of the Q Inspiration is scheduled to go on sale.

Look for more electrics from Infiniti to come to the U.S., as well—just maybe not big QX50 SUV.