Revision as of 10:39, 4 March 2014

Radical Batteries

They consist of stored nano sized gas-tight sealed cells and a reactor. In the cells carbon (or silicon) atoms have each three bonds to one corresponding handle and a single bond to an opposing equal but mirrored part. The single bonds act as reversible predetermined breaking points. Some nano-mechanical mechanism outside the sealed cells (the reactor or chemo-mechanical converter) is able to grasp the handles of an incoming cell pull them apart and put them into a lock position. The result is an energy loaded cell with some pairs of high energetic C-radicals (C atoms with open broken bonds) inside. The breaking process evens out the nonlinearity of the single bonds by breaking / building many bonds at the same in a zip style fashion and also handling multiple cell at the same time too. The breaking process furthermore transforms the motion into a wider ranging movement with less force (lever effect / gearing up). This way single bonds are not jerkily ruptured which would waste energy as heat.

unbonded
#### bonded  Chained
\|/  ####    ###########
 C   \|/     \|/ \|/ \|/
 •    C       C   C   C
      |       |   |   |
 •    C       C   C   C
 C   /|\     /|\ /|\ /|\
/|\  ####    ###########
####

Unlike thermal engines with a radical-zip-battery one can directly convert from chemical to mechanical energy without the detour over thermal energy. Without this detour (which would immediately split up the yielded energy into recoverable free and irrecoverable bound energy) we are no longer bound by the maximum efficiency of an carnough-process and can get (within limits) arbitrarily near 100% reversibility. The key to this is the complete positional control over every reactant (aka machine phase chemistry) which enables us to prevent the released energy from going rampant and disperse in all available thermic degrees of freedom which are partly irrecoverable.

Expected features of radical batteries:

• recyclability: potentially excellent - depends on AP - system design
• durability: very high - like any AP product they slowly but unavoidably accumulate damage from natural high energy radiation - if one pushes the limits with power density spikes the battery components average lifetime will decrease exponentially
• measurability: excellent - one can count while zipping - there is zero self discharge
• power density: a lot higher than todays best motor-sport engines
• efficiency: very high - no thermal detour
• energy density: mediocre but sufficient - there's a lot of encapsulating structure per broken bond
• resource consumption: no scarce elements are needed
• health hazards: probably very low - no heavy metals are used
• danger (when crushed): probably flammable, unlikely explosive - the use of non burnable SiO2 & Al2O3 as structural material is preferable over diamond

Note that like in a hydrogen system a complete radical battery systems include both an energy storage and an energy converter (reactor). The generated driving motion can either be delivered to electrostatic motors / generators or in one or more steps merged to an axle of macroscopic scale. Its desirable to pack the functionally into different parts (e.g. different microcomponents). This allows adjustable storage to converter ratios.

Entropic Batteries

An entropic battery may be implemented with a set of linear alkane molecules which are on both sides bond to handles. Those handles can be either pulled apart and fixated at their maximum separation thereby stretching the alkane completely straight or put together rather close allowing the alkane great freedom of movement.

        H H H H H H H H H H H H H H H
        | | | | | | | | | | | | | | |  
Handle1-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-Handle2
        | | | | | | | | | | | | | | |
        H H H H H H H H H H H H H H H

In the nano-comos every degree of freedom absorbs a quantum of energy that is proportional to the environments temperature (this energy is E = 3/2kT; see equipartition theorem). When the alkanes are completely stretched they have only a few degrees of freedom (DOFs) and store less thermal energy than in a natural unconstrained state. When the alkanes are contracted and chaotically curled up they provide many DOFs and store a maximal amount of thermal energy.

At non-zero temperatures the alkanes pull the handles together. So to draw energy from your battery you simply remove the handles from their locked positions and let them drive your workload. The emerging DOFs in the alkanes suck up the thermal energy of the environment effectively cooling the battery down. The reason behind this seemingly paradox behavior is that not the total energy but the Gibbs free energy is subject to minimization. Some more information can be found here: "rubber elasticity" and here: "entropic force"

To store energy into the entropic battery all the handles are pulled apart. The thermal energy is effectively wrung out out of the alkanes increasing the environments temperature.

Expected features of entropic batteries:

• recyclability: potentially excellent - depends on AP - system design
• durability: probably acceptable - carbon chains are especially sensitive to radiation damage - too fast charging can lead to thermal destruction
• measurability: excellent - one can count used handle pairs - zero self discharge
• power density: probably good - power extraction is limited by self cooling
• efficiency: probably acceptable for some applications - significant thermal losses since it's an inherent thermal process
• energy density: probably mediocre
• recource consumption: absolutely no scarce elements are needed
• health hazards: probably very low - no heavy metals are used
• danger (when crushed): inherently safe since it freezes when shorted - the use of silicone polymers would make it even safer.

Note that mechanosynthesis of the needed floppy polymers is beyond basic capabilities of productive APM systems and will require specialized tools.

Controlled molecular recombination

Radical batteries and entropic batteries do not allow for very high energy densities. To reach levels of gasoline one needs to turn to molecular energy storage substances.

With cheap AP-production one can avoid the need for (dangerous) high energy densities. Street bound vehicles may simply get their power induced over an AP road infrastructure. What can't work without high energy density storages are planes and ships in water air and space (not considering sails).

Molecular hydrogen as energy medium

energy storage cells could be implemented as nano-capsules filled with hydrogen that is compressed to fluid like densities (around thousand atmospheres). Compression heat is an efficiency issue. Whether and how single molecules can be extracted into machine phase has to be analyzed. The lack of available bonds to hold the reactants might complicate matters. Single hydrogen atoms can be hold by two lone pairs of oxygen if the structure is charged H₂O-H-OH₂⁺ but oxygen atoms in machine phase structures (R₂O-H-OR₂) cant be charged that much.

Nanosystems 13.3.8. Mechanochemical power generation