Decade of the battery

Predicting the technology that will define the next era of innovation

In 2015, Benedict Evans wrote a very influential piece called “The smartphone is the new sun”. By the middle of the 2010s, it was pretty clear that that decade would be defined in many ways by the mobile computing platform that Steve Jobs unveiled in 2007. For regular people, smartphones became the locus of their lives — an ever-present tether constantly connecting them to the digital world and allowing them to navigate the physical one. For industry, smartphones and the applications they enabled became a massive opportunity for investment and profit.

Now, however, it seems like we might be reaching the end of that rainbow. The basic reason is that with smartphones, IT companies have now harvested essentially all of people’s surplus attention and time. A new Pew survey of teens’ social media habits found that almost half of young people are online “almost constantly”, up from a quarter in the mid-2010s. And smartphone penetration in rich countries is around 80%. So it’s natural for both consumers and investors/entrepreneurs to be looking around for what technologies might enable another Cambrian explosion of innovation in the next decade.

Many people think that this technology is going to be machine learning/AI. But although I do think ML will indeed be very important, I’m going to make an argument that the general-purpose technology that will really transform our society is the battery.

This is interesting because it’s a bit of a swerve from the pattern of the last four decades. From 1980-2020, the innovations that reshaped our world were all in information technology — the PC, the internet, the smartphone and the social network. But batteries are an “atoms” technology — something that powers our physical world instead of helping us spin a new digital one. So the Decade of the Battery will look more like earlier decades, in which physical appliances like washing machines, refrigerators, and air conditioning were the hot new thing.

In fact, we can already see the shift in the 2010s — after all, batteries are what enabled smartphones.

The fundamental reason that batteries are becoming so important is simply that the technology has improved by leaps and bounds. Although batteries are improving on practically any metric, the two clearest indicators are cost and energy density. The cost of batteries, measured in dollars per kWh stored, has fallen by a factor of 42 since 1991 and by a factor of 2.5 since 2010:

Meanwhile, energy density more than tripled between 1990 and 2010:

Source: Ziegler & Trancik (2021)

The lion’s share of this improvement was due to R&D efforts, but industrial scaling effects are starting to have a significant impact as well.

But of course that still leaves the basic question of what batteries will be used for. I’m going to go through a bunch of use cases, from the obvious (cars and energy storage) to the not-so-obvious. But first, I should talk a bit about why batteries are such a general-purpose technology.

Batteries solve two fundamental problems at once