Methods of forming electrochemical cells are described. In some implementations, the method can include providing an electrochemical cell having an electrode with at least about 20% to about 99% by weight of silicon. The method can include providing a formation charge current at a first rate and at a second rate to the electrochemical cell. The first rate can be in a range from about C/100 to about C/10 and the second rate can be greater than about C/10.