Solid-state batteries are the longer term. They’re extra highly effective, compact, secure, and sustainable than Lithium-ion options, however true all-solid state batteries can’t be mass-produced cost-effectively. That’s why Kuxiu has gone semi-solid state for what it calls the “world’s most secure” energy financial institution, whereas calling dibs on it being a world first.
Kuxiu’s $79.99 S2 Qi2 5000mAh MagSafe Solid-State Power Bank helps Qi2 for 15W wi-fi charging. And with a 5,000mAh at 3.8V (19Wh) capability, it holds sufficient power to cost the smaller iPhone fashions from zero to full about as soon as. And regardless of utilizing the truncated “strong state” within the S2 title and product web page, the corporate confirmed to me that it’s constructed round a semi-solid state battery and that distinction issues.
I’ve been carrying the Kuxiu S2 for the previous few weeks. While I didn’t hammer, pierce, or tear the battery aside or expose it to fireplace like Kuxiu did, I can no less than affirm that it in any other case works as anticipated.
“Solid state” ambiguity
It’s not simply you, the battery business itself can’t appear to agree on what qualifies as a solid-state battery. There’s all-solid state, semi-solid state, and quasi-solid state, to call just some of the extra widespread phrases. All-solid state is the place the hype is and it’s the liquid-free battery of the longer term. But getting there at scale will possible require a couple of go-between steps.
Solid-state batteries use a strong electrolyte — the part liable for transferring electrically charged particles between the 2 terminals — however differ by way of the quantity of liquid current. If the quantity of the liquid electrolyte is between 5 and 10 % of the load of the lively a part of the battery then it’s sometimes categorized as semi-solid state. Less than 5 % and it’s quasi-solid state. 0 %, you guessed it: all-solid state. The battery contained in the Kuxiu S2 incorporates a solid-liquid blended electrolyte that varieties a gel-like consistency that’s seen within the video above. It subsequently suits the definition of semi-solid state, in accordance with the corporate.
So why is “Battery Type: Li Polymer Battery” listed within the high-quality print on the label stamped onto Kuxiu’s S2 energy financial institution? LiPo batteries have been round in energy banks for years, and endure from comparatively quick lifespans and low power densities — precisely the other of what Kuxiu claims for the brand new S2. Turns out that the strong electrolyte inside solid-state batteries will be comprised of varied supplies like ceramics and sure, polymers. So Kuxiu’s declare is probably going true, the S2 is a Li Polymer battery that’s additionally a solid-state battery, or semi-solid state to be exact. Therefore, it might very effectively be the world’s first energy financial institution to make use of a solid-state battery as the corporate says.
For comparability, the Lithium-ion battery discovered within the energy financial institution you possible have laying round at residence incorporates over 25wt % liquid, making it extra liable to leakage, thermal runaway, and hearth than the S2. Kuxiu’s energy financial institution doesn’t profit from each benefit of going strong state — like ever larger power densities and better security achieved with all-solid state batteries — however it’s a step in the proper course. Notably, Kuxiu can mass produce the S2 right this moment utilizing many current manufacturing processes to assist maintain prices down.
Companies like Anker will inform you {that a} typical 5,000mAh energy financial institution often begins to degrade after 300–500 charging cycles. At that time, it’ll solely maintain about 60 to 80 % of the unique capability. Kuxiu tells me that the S2 is sweet for 1,000 charging cycles earlier than capability drops to 80 %. So, whereas it prices about 60 % greater than a comparable liquid-based energy financial institution from firms like Anker or EcoFlow, it ought to simply final twice as lengthy earlier than you see any noticeable degradation.
Kuxiu claims an improved 360Wh/kg power density in comparison with 300Wh/kg for liquid cells. The S2 is definitely compact and light-weight at 10.4 x 6.7 x 1.0cm / 145g, which makes it extra moveable than EcoFlow’s direct competitor which measures 10.8 x 7.0 x 1.44cm / 180g. But EcoFlow’s 5,000mAh energy financial institution additionally features a kickstand and 30W of extra highly effective bidirectional wired charging. Anker, nevertheless, edges out the S2 in dimension and weight with its 5K energy financial institution measuring 10.2 x 7.0 x 0.9cm / 120g. But that possible says extra in regards to the supplies used to embellish and defend the batteries than their respective power densities.
As a MagSafe-compatible Qi2 energy financial institution, the Kuxiu S2 mechanically begins charging as quickly as its 16 N52 magnets seize maintain of my iPhone 15 Pro. Those magnets are sturdy and preserve the bond at the same time as I slip the combo right into a unfastened pocket or bag. Still, they’re not proof against a well-placed bump that might ship the battery to the ground. That might spell bother for the aluminum S2 sandwiched between two sheets of Corning Gorilla Glass, every protected by an “explosion-proof movie.” After three weeks of careless dealing with, my S2 assessment unit has a small however noticeable nick on the shell, however in any other case appears to be like new.
Sadly, the underside of the battery extends past my iPhone 15 Pro to upset the symmetry I’d possible take pleasure in when paired with considered one of Apple’s bigger Qi2-compatible iPhones. At least the cameras aren’t obscured. I might additionally do with out all of the specs listed on the skin of the unit. The energy financial institution does work with or and not using a MagSafe-compatible case on my iPhone, however the case does trigger the S2 to warmth up barely (making it much less environment friendly) to assist overcome the hole.
The USB-C port on the underside of the S2 options passthrough, so you may cost the facility financial institution and a magnetically hooked up iPhone or AirPods on the similar time. Charging the S2 solo from my MacBook’s wall charger took the facility financial institution from zero to full in a moderately sluggish 90 minutes.
The energy financial institution can even cost non-Qi2 gadgets due to its bidirectional USB-C port. That’s helpful to juice up gadgets like over-the-ear headphones and Android telephones at as much as 20W. The S2 additionally proved able to topping up my beefy 14-inch MacBook Pro, albeit very, very slowly.
A double-tap on the button alongside the underside edge places the facility financial institution right into a low-current mode. That manner, the S2 can cost small gadgets like good rings and wi-fi earbuds whereas bypassing automated shutoff mechanisms designed for extra power-hungry gadgets. Smart, however not distinctive to the S2.
I do want that Kuxiu put a kickstand on the S2 like so a lot of its opponents. At least it’s obtainable in each black and titanium colours to raised match your cellphone.
1/4
Misleading battery advertising and marketing apart, I’m very impressed by the Kuxiu S2 Qi2 5000mAh MagSafe “Solid-State” Power Bank by way of what it’s and what it guarantees. Yes, it’s dearer than equally specced energy banks utilizing conventional liquid electrolytes, however the S2’s semi-solid state battery ought to show to be safer and cheaper than opponents over its for much longer lifetime.
Photos by Thomas Ricker / The Verge
