"Silicon-based anodes towards market penetration"

Batterimarkedet for Li-ion vokser raskt og forventes å være i raskt endring i det neste tiåret. Markedet vil gå fra en forbrukerelektronikk dominert til en fase dominert av elektroniske kjøretøy (EV). En ekstraordinær økende etterspørsel etter batterier betinger imidlertid nye og tilgjengelig råmaterialer til å komme inn i markedet for å levere bedre ytelse. Blant slike nye materialer er silisium og silisiumbaserte materialer. Silisium har høyest teoretisk lagringskapasitet av potensielle materialer,- og tester med silisumbaserte anoder har demonstrert forbløffende høye lagringskapasiteter. Men det er noen utfordringer knyttet til silisiumbaserte anoder. Dette prosjektet har som mål å bidra til å løse disse utfordringene gjennom bruk av Elkems silisium, og optimalisering av denne gjennom ulike strategier. Kunnskap og erfaring om dette materialet er opparbeidet gjennom tidligere interne og Forskningsrådstøttede prosjekter. Optimaliseringen av det aktive materialet - silisium - har fortsatt med påfølgende batteritesting. Resultatene viser at det er mulig å bedre batteriegenskapene gjennom endring av noen de fysiske og kjemiske egenskapene til silisium som Elkem produserer.

The SiBANODE project included development of the silicon-based material, demonstration of scale-up production method, design of cell, demonstration in coin cells, and pouch cells. The challenging goal of extending the cycle lifetime to 1000 cycles has unfortunately not been achieved. Stability of the material was studied by state-of-the art electron microscopy, in addition to molecular modelling. Some material properties and surface design of the material needs further investigation in order to close the gap between obtained results and target for the anode material.

SiBANODE is aimed to develop silicon-based materials which will be utilized in the lithium-ion batteries delivering high capacity while keeping long lifetime. Li-ion battery is a quickly expanding technology rapidly penetrating various markets and applications. Originating from the portable electronics, Li-ion batteries are currently widely utilized in the alternative applications, such as transportation and stationary energy storage. However, an extraordinary growing demand for batteries encourage new materials to enter the market to deliver better performance. Those emerging materials include silicon and silicon-based compounds. Silicon introduced as promising anode material revealed its potential by demonstrating astonishing storage capacity. Nowadays utilized only as a small fraction in the commercial anodes of Li-ion batteries, silicon represents a major scientific and technological challenge in the field. The wide use of silicon in anodes is strongly limited by the intrinsic properties of silicon. The ability of this material to accept 4.4 atoms of lithium per atom of silicon results in enormous expansion and contraction during lithiation and corresponding delithiation occurring during battery cycling. Such volume change significantly limits the application of this technology and have been a topic of extensive research over the last decade. The present project is aimed to solve those problems by utilizing battery-grade silicon produced by Elkem and enhancing its stability by two routes. The first include the preparation of the alloyed silicon-based materials, which due to a slightly different functioning, will deliver long-term stability while keeping the benefits of the parenting silicon. Second alternative strategy will include chemical modification of the existing silicon by tuning the microscopic and surface properties of silicon particles. SiBANODE utilizes long-term experience in manufacturing, characterization and research of Elkem, Sintef and IFE.