Public Funding for Sigma Lithium Limited

Li-ion batteries are the most widely used rechargeable battery technologies in various scale application from small portable electronic devices, to electric vehicles and grid storage. Employing graphite as the anode material, they offer energy densities of ~100-265 Wh/kg. However, high energy densities (\>200 Wh/kg) are only reached at slow charge rates. Metallic Li is a superior anode offering significantly higher gravimetric/volumetric energy densities due to its low density and redox-potential. Additionally, the main processes during charge/discharge with Li metal anodes are Li deposition/stripping instead of Li intercalation/deintercalation which affect the overall kinetics. Hence, switching from conventional graphite anodes in Li-ion batteries to Li metal anodes offers a step-change in both mileage and charge/discharge rates for electric vehicles and can answer the demand for high energy and power applications. Sigma Lithium (SL) have developed an advanced 3D-Li anode battery technology which is inherently safer, cost-competitive, and exhibits higher specific energy/power densities against current state-of-the-art. SL's 3D‑Li anode offers a lightweight, mechanically robust, and porous scaffold coated with Li, which increases the gravimetric/volumetric energy densities and enables the safe use of highly reactive Li by reducing local current densities. A platform solution, SL's innovative battery technology can be applied to multiple battery chemistries. SL are now working with Gen2Carbon to optimise the composition of the carbon fibre scaffold for improved battery performance, while creating a sustainable product from recycled carbon fibre materials which would otherwise have gone to landfill.

Sigma Lithium proposes a proprietary patented method of forming porous 3D metallic lithium electrodes for applications in lithium-based batteries. This metallic lithium electrode technology will enable the creation of a new generation of batteries, with higher energy density, longer cycle counts, and improved efficiency in high-power applications. Our technology will bring about a step change in the performance of electric vehicles.

Manufacturing advances and miniaturisation are typically focussed upon as key enablers for new technologies, however this has led to a paradoxical state where manufacturing capabilities exceed our ability to power devices. In this increasingly mobile world, the focus has shifted to batteries as the key to the realisation of the next generation of autonomous robotics, computing, utilities, and flight. In 2010, the Zephyr, an Unmanned Aerial Vehicle, (UAV) made by the UK firm QinetiQ achieved continuous flight for over 2 weeks setting an undefeated global record. After its success, the team noted that one of the most significant innovations incorporated within their design was a new, highly efficient battery design with dramatically increased energy density. This reduced Zephyr’s weight while allowing the plane to store more charge, so that it could charge by day to fly continuously within the night. With the next generation of batteries, planes like the Zephyr will be able to fly continuously for months or years at end serving as readily deployable quasi-satellites which can relay communications in disaster zones, closely monitor ocean weather for hurricanes, and assist in search and rescue efforts by offering real-time mapping coverage. These batteries will also be able to power the next generation of prosthetics by powering more power-intensive, sophisticated control electronics. These myoelectric and neuroprosthetics will give wearers greater independence by lasting throughout their day without needing charge while offering precise control and feedback. Sigma Lithium (SL) is developing a new electrode which will enable these applications and more by doubling the energy density of Li-ion batteries. Unlike exotic chemistries, SL’s advances can be directly integrated with existing cells to boost capacity in a relevant timescale today.

The Oxford based Sigma Lithium Ltd has developed a new anode material for primary and rechargeable lithium and lithium-ion batteries. The new technology has a potential to deliver a two fold increase in energy density for advanced lithium-ion batteries. The company is applying for the patent protection to secure its priority for batteries used in a variety of applications including energy storage and electric vehicles.