A fascinating read, Hasok Chang (the most engaging company btw) has looked deep into the long standing and still prevailing confusion about the phenomenon known as 'Contact Potential Difference'. This is the mechanism which Frank Gordon and Harper Whitehouse believe lies at the heart of the LEC phenomenon - as do I. The LEC is based on the amplification of this effect seen, sometimes discussed, sometimes dismissed, then revived again going back over several centuries- back to the work of Volta in fact.
Wikipedia says "The Volta potential (CPD) is seen when two different neutral metal surfaces are brought into electrical contact (even indirectly, say, through a long electro-conductive wire), electrons will flow from the metal with the higher Fermi level to the metal with the lower Fermi level until the Fermi levels in the two phases are equal. Once this has occurred, the metals are in thermodynamic equilibrium with each other (the actual number of electrons that passes between the two phases is usually small). Just because the Fermi levels are equal, however, does not mean that the electric potentials are equal. The electric potential outside each material is controlled by its work function, and so dissimilar metals can show an electric potential difference even at equilibrium. The Volta potential is not an intrinsic property of the two bulk metals under consideration, but rather is determined by work function differences between the metals' surfaces. Just like the work function, the Volta potential depends sensitively on surface state, contamination, and so on."
Dr Chang says.
Much of the long controversy concerning the workings of electric batteries revolved around the concept of the contact potential (especially between different types of metals), originated by Alessandro Volta in the late eighteenth century. Although Volta’s original theory of batteries has been thoroughly rejected and most discussions in today’s electrochemistry hardly ever mention the contact potential, the concept has made repeated comebacks through the years, and has by no means completely disappeared. In this paper,
I describe four salient foci of its revivals: dry piles, thermocouples, quadrant electrometers, and vacuum phenomena. I also show how the contact potential has maintained its presence in some cogent modern scientific literature. Why has the death of the Voltaic contact potential been such an untidy affair? I suggest that this is because the concept has displayed significant meaning and utility in various experimental and theoretical contexts, but has never been successfully given a simple, unified account. Considering that situation, I also suggest that it would make sense to preserve and develop it as a multifarious concept."
Read and enjoy. I think that the work of Gordon and Whitehouse ( Stevenson plus Matt Lilley and mine) shows that there are ways in which the Volta potential can be enhanced and made more durable.. Notice that comment from Wikipedia's piece "the Volta potential depends sensitively on surface state, contamination, and so on."