Low Self-Discharge, High-Voltage Supercapacitors Using Porous Carbon

March 23, 2026 by Maya Posch 13 Comments

Supercapacitors rely mostly on double-layer capacitance to bridge the divide between chemical batteries and traditional capacitors, but they come with a number of weaknesses. Paramount among these are their relatively low voltage of around 2.7 V before their electrolyte begins to decompose, as well as their relatively high rates of self-discharge. Here a new design using lignin-derived porous carbon electrodes and a fluorinated diluent was demonstrated by [Shichao Zhang] et al., as published in Carbon Research, that seems to address these issues.

Most notable are the relatively high voltage of 4 V, an energy density of 77 Wh/kg and a self-discharge rate that’s much slower than that of conventional supercapacitors. In comparison with these supercapacitors, these demonstrated versions are also superior in terms of recharge cycles with 90% of capacity remaining after 10,000 cycles, which together with their much higher energy density should prove to be quite useful.

This feat is accomplished by using lignin as the base for the carbon electrodes to make a highly porous surface, along with the new electrolyte formulation consisting of a lithium salt (LiBF₄) dissolved in sulfolane with TTE as a non-solvating diluent. The idea of using lignin-derived carbon for such a purpose has previously been pitched by [Jia Liu] et al. in 2022 and [Zhihao Ding] in 2025, with this seemingly one of the first major applications we may be seeing.

Although the path towards commercialization from a lab-assembled prototype is a rough one, we may be seeing some of these improvements come to supercapacitors near you sooner rather than later.

Storing Solar Energy As Ice For Air Conditioning

March 22, 2026 by Maya Posch 84 Comments

Thermal energy storage is pretty great, as phase-change energy storage is very consistent with its energy output over time, unlike chemical batteries. You also get your pick from a wide range of materials that you can either heat up or cool down to store energy. Here, the selection is mostly dependent on how you wish to use that energy at a later date. [Hyperspace Pirate] is mostly interested in cooling down a house, on account of living in Florida.

As can be seen in the top image, the basic setup is pretty straightforward. PV solar power charges a battery until it’s fully charged. Then an MCU triggers a relay on the AC inverter, which then starts the cooling compressor on the water reservoir. This proceeds to phase change the water from a liquid into ice. The process can later be reversed, which will draw thermal energy out of the surrounding air and thus provide cooling.

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How A Belkin USB Charger Pulls Off A 3 Milliwatt Standby Usage

March 22, 2026 by Maya Posch 20 Comments

Belkin charger standby power. (Credit: Denki Otaku, YouTube)

A well-known property of wall warts like power bricks and USB chargers is that they always consume some amount of power even when there’s no connected device drawing power from them. This feels rather wasteful when you have a gaggle of USB chargers constantly plugged in, especially on a nation-sized scale. This is where a new USB-C wall charger by Belkin, the BoostCharger Pro, is interesting, as it claims ‘zero standby power’, which sounds pretty boastful and rather suspect. Fortunately, [Denki Otaku] saw fit to put one to the test and even tear one down to inspect the work of Belkin’s engineers.

Naturally, no laws of physics were harmed in the construction of the device, as ‘zero standby power’ translated from marketing speak simply means ‘very low standby power usage’, or about 3 milliwatt with 0.3 mA at the applied 100 VAC.

Fascinatingly, plugging in an e-marker equipped USB-C cable with no device on the other end caused this standby usage to increase to about 30 mW, clearly disabling the ‘zero standby’ feature. With that detail noted, it was time to tear down the charger, revealing its four PCBs.

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Reviving A Cursed Sun SPARCstation IPX

March 21, 2026 by Maya Posch 21 Comments

SPARCstation IPX running Solaris 2.6. (Credit: This Does Not Compute, YouTube)

The best part about retro computing is the idea that you’ll save some poor system from being scrapped and revive it to a working state, at which point you can bask in the glory of a job well done. That’s when reality often strikes hard, and you find yourself troubleshooting a maddening list of issues as you question everything about your life choices. Such was the case with [This Does Not Compute] over at YouTube with a Sun SPARCstation IPX that decided to put up a big fight.

This is the second video of a series. In the first installment, the PSU was repaired, and a boot failure was diagnosed. The system’s onboard diagnostic led to the assumption that one of the 8 kB SRAM ICs was defective. You can readily get SRAM replacements, so it seemed to be an easy fix. Unfortunately, the fun was only beginning as the system reported the exact same error after the SRAM was replaced.

After flipping a virtual table, the mainboard was swapped with a donor one from a scrapped laptop system. With this, it booted, but the video output showed only vertical lines. Obviously, the solution here was to insert a replacement video card, which not only fixed the display output but also demonstrates once again that you can fix many vintage computing issues by simply replacing hardware.

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Slug Algorithm For On-GPU Rendering Of Fonts With Bézier Curves Now In Public Domain

March 20, 2026 by Maya Posch 15 Comments

The Slug Algorithm has been around for a decade now, mostly quietly rendering fonts and later entire GUIs using Bézier curves directly on the GPU for games and other types of software, but due to its proprietary nature it didn’t see much adoption outside of commercial settings. This has now changed with its author, [Eric Lengyel], releasing it to the public domain without any limitations.

Originally [Eric] had received a software patent in 2019 for the algorithm that would have prevented anyone else from implementing it until the patent’s expiration in 2038. Since 2016 [Eric] and his business have however had in his eyes sufficient benefit from the patent, making it unnecessary to hold on to it any longer and retain such exclusivity.

To help anyone with implementing their own version of the algorithm, there is a GitHub repository containing reference shader implementations with plenty of inline comments that should help anyone with some shader experience get started.

Although pretty niche in the eyes of the average person, the benefits of using on-GPU rendering of elements like fonts are obvious in terms of rendering optimization. With this change open source rendering engines for games and more can finally also use it as well.

Thanks to [Footleg] for the tip.

Conway’s Game Of Life With Physical Buttons

March 20, 2026 by Maya Posch 13 Comments

Conway’s Game of Life excels in its simplicity, creating a cellular automaton on a 2D grid where each cell obeys a set of very simple rules that determine whether a cell is ‘alive’ or ‘dead’. After setting an initial condition the ‘game’ then evolves naturally from there, creating an endless series of patterns as a simplified form of bacterial evolution. Of course, setting an initial state and then watching cells light up or fade away seems like a natural fit for light-up buttons. After struggling with intrusive thoughts related to such a project for a while, [Michal Zalewski] finally gave in, creating a pretty amazing looking result.

Although there is no set size for the game board, [Michal] was constrained by his budget for the selected NKK JB15LPF-JF tactile buttons, resulting in a 17×17 matrix. That’s 289 buttons, for those keeping score, which comes down to over $1,000 over at e.g. Digikey even with quantity-based pricing. Add to this the custom PCB and a Microchip AVR128DA64 squeezed in a corner of said PCB to run the whole show and it’s quite the investment.

Finishing up the PCB, driving the lights is done with a duty cycle as the matrix is scanned along with detecting inputs in a similar manner. This required the addition of MOSFETs and transistors, the details of which can be found in the downloadable project files, along with the firmware source code. In the article a video of the board in action can be watched, allowing one to admire the very pretty wooden enclosure as well.