Update on Natron Energy, sodium-ion battery builder with $35M from ABB, Khosla, Chevron


We reported on battery builder Natron’s $35 million investment round last week — but wanted to provide an update on the company’s markets and technology from people familiar with the firm.


Natron Energy, a Santa Clara, Calif.-based startup developing a battery using Prussian blue analogue electrodes and a sodium-ion electrolyte, raised $35 million in series D funding led by ABB Technology Ventures, NanoDimension Capital and Volta Energy Technologies. Return backers Chevron Technology Ventures, Khosla Ventures, and Prelude Ventures also participated. Fluxus Ventures has also invested in the firm which has received a total of more than $50 million in venture funding and more than $5 million in ARPA-E and DOE funding.

Natron is the former Alveo which was founded in 2012, based on work within the Huggins Group by co-founder Dr. Colin Wessells at Stanford University.

Although Prussian blue provides modest energy density, the startup claims that Prussian blue is so earth-available and inexpensive that it could provide a cost-effective and sustainable answer for stationary energy storage.

According to its website, Natron is developing batteries for “data-center UPS, electric forklifts, smart grids/microgrids, and renewables support. Natron’s batteries survive tens of thousands of deep discharge cycles, can be fully charged or discharged in just minutes, and cost significantly less than incumbent lead acid batteries.”

Update 1: The startup is “going after some applications that have been traditionally lead acid and some that have been lithium ion. Think ultra-fast discharges, unbelievable cycle lives, low cost, and non-toxic materials,” according to someone close to the company.

Update 2: “Tens of thousands of cycles is an impressive feat,” but this is only valuable for certain applications. Note that “daily cycling for 10 years is only 3,650 cycles. And extra cycles beyond year twenty don’t make much contribution to net present value. So you need applications that are cycling multiple times per day. Maybe battery-powered EV fast chargers? Buses that run 24/7? Grids that are highly peaky?”

Update 3: Water-based chemistries have low voltage and low energy density, which adds to cost. If the battery stores 10x less energy per cell, then the system will need 10x more cells to store the same amount of energy. Li-ion competitors often shrug off low energy density by saying ‘we are stationary, size/weight doesn’t matter’, but size/weight correlates to cost, so it does matter. Each kilo of material and each cell manufacturers bears a cost.

U.S. energy storage deployments reached roughly 500 MW in 2019 — of which only a few megawatts were non-lithium-ion chemistries. Lithium-ion batteries have their disadvantages — high reactivity, conflict minerals and environmental risk — but they are the clear-cut dominant winner in today’s battery race.

Dislodging lithium ion

Investors seem fascinated by energy storage this year, the long-duration variety in particular. Within the last few months, we’ve seen these energy storage investments.

  • Eos Energy Storage with its four- to six-hour duration zinc battery chemistry announced its intention to go public via a SPAC. Eos has spent over $160 million from investors including AltEnergy, Holtec International, Reservoir Capital Group, and Generation Capital .
  • Form Energy claims its aqueous air battery provides 150-hour duration storage. Form Energy intends on deploying a 1 MW/150 MWh system with a Minnesota utility before 2023, an unprecedented energy storage duration if successful. Form has raised over $50 million in funding from investors Eni Next, MIT’s The Engine, Breakthrough Energy Ventures, Prelude Ventures, Capricorn Investment Group and Macquarie Capital.
  • Quidnet looks to use “excess” renewable energy to store pressurized-water under ground at dry oil and gas wells. Bill Gates led a $10M investment in the startup.
  • QuantumScape, a solid-state lithium ion battery builder, received up to $200 million from Volkswagen last month. Other investors in QuantumScape include Kleiner Perkins, Prelude Ventures, Lightspeed Venture Partners, Capricorn Investment Group, and Khosla Ventures.

Despite the blue-chip investors and rock-star entrepreneurs at QuantumScape and Eos and Natron — it’s a testament to the difficulty of developing a new battery technology that it has taken more than a decade to bring these products to the edge of industrial production.

Natron is hiring.

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