(EV) Batteries in 2026
Relative recently, I bought an EV and like many people that purchase quickly turned into a battery rabbit hole. Once you start reading, you get hit with two competing impressions. One is that today’s lithium-ion packs are mature, reliable industrial products. The other is that a revolution is always around the corner, usually wearing the label solid-state.
I wanted to get a better picture of the current developments for myself and share what I learned in this post. What do modern batteries look like, what is improving, and how do recent papers fit into that trajectory?
Where batteries stand today
Before we get to the new stuff, we have to look at what is actually inside a battery. A lithium-ion cell is analogous to a rocking chair for lithium ions. There are two electrodes: an anode (negative) and a cathode (positive), separated by a porous separator soaked with electrolyte. When you charge, you use energy to push lithium ions out of the cathode and into the anode, where they get stored in a host structure (usually graphite). When you drive, the ions head back to the cathode through the electrolyte, while the electrons take the outside route through the circuit and do useful work on the way. Battery research comes down to three main goals: packing more lithium into the electrodes (capacity), helping ions move faster (power and charging speed), and keeping the materials from falling apart during repeated cycling (longevity).
Modern rechargeable batteries go back further than I realized, at least to Planté’s lead-acid cell in 1859 (Britannica). Lithium-ion, though, is a much newer story. The key components were developed from the 1960s onward, and the first commercial lithium-ion batteries arrived in 1991.
Most EVs on the road today still run on lithium-ion cells with a liquid electrolyte, and most of the progress in the last decade has been a long chain of incremental engineering improvements. Often science news focuses on the big leaps - which don't get me wrong, do exist and can have huge impact on the world - but the small incremental steps often lead to large developments on their own.
On the cathode side, high-nickel layered oxides (NMC - Lithium nickel manganese cobalt oxides and NCA - lithium nickel cobalt aluminium oxides families) dominate many longer-range vehicles because they pack more energy into a given mass and volume. Their layered structure is part of the appeal: lots of room for lithium, good energy density, and good long-term performance. LFP (Lithium iron phosphate) is the other big pillar. LFP has a more rigid crystal framework that tends to be more tolerant of heat and abuse and can deliver long cycle life, with lower energy density as the trade-off. You can imagine that for some purposes and regions this could be more useful. The IEA reports that LFP supplied over 40% of global EV battery demand by capacity in 2023, with adoption patterns that vary strongly by region.
Source: IEA – Electric vehicle battery sales share by chemistry and region, 2022–2024
On the anode side, graphite is still the workhorse, increasingly blended with silicon. Silicon can store far more lithium than graphite, which is why it keeps coming back into the conversation. It also swells dramatically when lithiated, which is obviously a problem as expansion can form cracks and break contact, which lowers battery life, which is why it keeps coming back into the conversation.
In terms of improvements, costs of lithium-ion battery have continued to fall due to these small improvements we mentioned before. That matters for consumers because price and availability shape the market faster than most chemistry headlines do.
Battery lifetime is also improving in the boring, important way. Geotab’s 2024 analysis estimates average EV battery degradation around 1.8% per year, slower than their earlier work suggested. Individual packs vary a lot, yet the overall direction is clear. Modern packs usually fade gradually and is usually determined by temperature exposure, how long the battery is at a high state of charge, and charging habits.
What the next step looks like
Battery development right now is a mix of two lanes running in parallel.
The first lane is continued optimization of today’s lithium-ion platform, especially on the anode and the interphase (the thin layer that forms at the boundary of the electrode and electrolyte). This is where silicon-rich anodes, better electrolyte additives, and better formation protocols live. The fight is to get silicon’s capacity without paying for it in cracked particles and interphase damage. A good example is recent work on making silicon-heavy anodes more practical at the full-cell level. Quan and colleagues (National Science Review, 2025) focus on improving initial Coulombic efficiency, meaning the fraction of lithium that remains usable after the very first charge, using prelithiation and interphase engineering. They made the silicon easier to prelithiate chemically, and make the first interphase less self-destructive. In their system, an amorphous, columnar silicon structure with internal void space helps accommodate expansion and also shifts the lithiation behavior in a way that enables controlled chemical prelithiation (they tune it by immersion time). The point of this is to start the full cell with less missing lithium and with a more stable early-cycle interphase. The consumer-facing payoff is straightforward. If silicon can be pushed further without ruining cycle life, you get more range per kilogram and per volume unit, and you do it without reinventing the whole battery.
The second lane is solid-state, which replaces the liquid electrolyte with a solid ion conductor. One of the benefits is safety (we're getting rid of the flammable liquid conductor), but the bigger reason people keep chasing it is packaging more energy into the same footprint (solid state is estimated that it will be upwards of 500 Wh/kg compared to the 200-300 Wh/kg of lithium-ion). Solid electrolytes are often paired with lithium-metal (or very thin lithium) anodes, which can, in principle, lift cell-level energy density by removing a lot of graphite and copper from the stack. A 2025 Nature Energy paper by Burton et al. puts hard numbers and constraints on that promise, showing how thin-lithium designs can move you toward very high gravimetric (energy/mass) and volumetric energy (energy/volume) density, while also clarifying where efficiency and manufacturability bottlenecks show up. One of these is that if your lithium layer is thin (20 micrometer or so), you can easily get irreversible damage that leads to large long-term losses. With thin layers also comes manufacturing difficulty; how do we get consistent thickness and low defects? Lastly, solid-solid contact remains hard, especially when combining with pressure, creep and cracking. This gets worse in real life, when the batteries are driven around.
On the cathode side of solid-state, the engineering challenge is equally difficult. You need ionic and electronic pathways through a composite that stays mechanically stable over long cycling. Usually, this is made with a mixture of cathode poweder, mixing in solid electrolytes and adding conductive additive to help electrons go through. However, this leads to brittle structures with lots of problems. Cui and colleagues (Nature Energy, 2024) report a cathode homogenization strategy for all-solid-state lithium batteries where they cold-press from a single low-strain material that can still conduct well. This leads to smaller volume change when cycling, and it is pretty much 100% active mixed-conducting phase instead of the fragile, additive composite. These are the kinds of inventions that can help push the practical boundaries of solid-state into the market.
Industry timelines reflect the same tension between promise and manufacturing reality. Toyota has repeatedly pointed to a 2027 to 2028 window for introducing solid-state EVs at some level, alongside an emphasis on production constraints. Progress updates from companies like QuantumScape focus on scaling separator production equipment, which is one of the current manufacturing bottlenecks. That is the part of the progress where big promises can turn into supply chains (like how we currently don't think about lithium ion production and engineering), or disappear slowly.
So, will today’s EV batteries become obsolete soon? There will be better batteries, and there will be cars that charge faster and go farther. The more important point is that change is arriving as layered improvements, with solid-state likely appearing in steps and limited volumes before it shows up everywhere. For owners, I don't expect lithium ion battery to suddenly disappear and lose their value. We should keep up with current news though, as it could be very possible that solid-state batteries will start to overtake lithium within the next 10 years based on the amount of development being poured into them.